With Pistachio & Radish Green Pesto
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To me, red radishes occupy a strange place in the produce pantheon. They look so bright and happy and crisp, and I’m always happy to see them – and yet I rarely pick them up and add them to my basket. Sure, they’re delightful in salads, but it’s hard to get excited about that over and over again. But radishes are hiding a secret that really needs to be shared – they are utterly amazing when roasted.
A roasted radish is marvelously transformed. The sharp, peppery bite mellows considerable, leaving a delightful (though difficult to describe) pleasingly-pungent flavour that manages to be both earthy and buttery at the same time. And let’s not forget the pesto.
My first foray into radish green pesto was born of necessity. I grew radishes on a balcony garden a number of years ago, and I was overwhelmed by my success. Not only did I end up with lovely radishes, but I had an absurd bounty of leafy-green above-ground growth. I abhor wasting greens, and I’m always looking for new ways to use them. If you’ve never used radish greens, (please forgive this painfully obvious-sounding explanation) they taste a lot like radishes, only milder and greener. To my mind, this makes them an ideal pesto ingredient, because they pack some punch. When you think about it, pesto is packed with absurdly bold flavours. Raw garlic, strong cheese, and (in the case of traditional Ligurian Pesto Genovese) basil and pine nuts. Those are not flavours that scream ‘mild.’ So when it comes to breaking with tradition and varying the recipe, you want to remain assertive. Radish greens obviously lack the distinctive punch of basil, but they do pack a peppery bite that works with (and perhaps amplifies) the raw garlic. As for the nuts, pistachios were the ideal choice here thanks to their distinctive but comparatively mild flavour. They bring a lot to the pesto, but they’re not as overwhelming as pine nuts (plus they’re significantly cheaper, so win-win). I dive into pesto making more below in the recipe notes, so keep reading for tips and tricks.
If you do decide to make this, I’d encourage you to follow the recipe fairly closely the first time, then start playing and modifying after that. Pesto is one of those things that (to my mind) benefits from a personal touch, but can be easily messed up if you don’t have any experience with it. That being said, don’t be constrained by serving styles; I went with pasta here and I couldn’t stop eating it, but it’s also incredible on bread or toast. If you’re keeping things gluten-free, you could go with a GF pasta, but I think both the radishes and the pesto would be incredible with polenta. I’m also not opposed to just straight-up eating this with a spoon.
Alright, this is not a complicated meal AT ALL, but it’s one of those meals that will go better if you’re familiar with the ingredients and willing to dig through some VERY strong opinions about how things should and shouldn’t be done. I know this notes section looks a bit intimidating, but it’s here for clarity’s sake, and doesn’t reflect the complexity of the meal. I’ve included all of this info because pesto, like most Italian foods, evokes some pretty strong and very mixed opinions in people. I’m going to do my best to explain what I do and why. That way, whether you choose to follow my methods or to vary them, you’ll have a good understanding of the impact on the final product.
I used slender French breakfast radishes here because they’re tasty and adorable. But don’t feel like you have to use them – standard red grocery store radishes will work very well too. In theory, you could try this with Asian radishes as well (though they can be quite tricky to find with greens attached), but I would expect a somewhat milder end product. Black radishes, whiles gorgeous and amazing, are VERY assertive when raw, and I have no idea how they would roast up. Something to explore I suppose. Additionally, you’re going to want to use small radishes in order to make the roasting process feasible; very large radishes would need to be cut into smaller pieces, which will impact your presentation and add to your prep time.
Roasted radishes are actually pretty forgiving, so don’t fret too much. The key is HEAT. You’re going to use a hot oven, and I personally like using a heavy, pre-heated cast iron pan. This gives a very nice sear to the radishes while allowing them to cook evenly. If you don’t have a good cast iron pan (BUY ONE), you can use a heavy, preferably dark baking sheet.
When choosing radishes, you’ll want to pay as much attention to the greens as you do the roots. Radish greens are frequently on the dirty/sandy side, but don’t let that deter you – simply soak them in cold water and gently clean them up. Small holes in the leaves are very common (they’re frequently caused by flea beetles) and are not a problem. Avoid overly yellowed or heavily wilted/mushy leaves. Home-grown radishes are ideal for this meal, but do note that many varieties will develop small spines on the stalks and leaf undersides. They get more-or-less obliterated by the pesto-making process, but you might want to trim away any particularly large and well-defended stalks or heavy leaf-veins.
Alright folks, it’s caveat time: this is not traditional pesto (which is, I hope, painfully obvious). That being said, while the ingredients depart from Pesto Genovese, the processes, ratios, and flavours have all been considered thoughtfully. I will also note that I like my pesto on the thicker/chunkier side – I’ve never been particularly fond of very thin/runny pesto, so that’s not what I make. If you like it thinner, I’ve given some tips on dealing with that below in the olive oil and mortar/pestle vs. food processor sections.
This section owes a great debt to this wonderful Serious Eats article on pesto making. It was very helpful when I was tweaking and developing my own pesto recipe, and I’ll be referring to it several times below. I encourage you to give it a good read.
Traditional Pesto Genovese is made with a combination of Parmigiano-Reggiano and Pecorino Fiore Sardo (a Sardinian sheep’s milk cheese). Good parmigiano is pretty easy to find these days, and if you buy it in big pieces it’s not too pricey. Pecorino Sardo is not cheap, and it can be very hard to find. For that reason, it’s generally substituted with Pecorino Romano here in North America. Pecorino Romano is a bolder, more assertive cheese, but I think it still works amazingly well in pesto.
Now, with all that being said, you can still make amazing pesto with parmigiano alone. True, it will lack some of the funky tang (or tangy funk) of pecorino, but it’s still amazing. I’ve done it many times when I didn’t have pecorino lying around. You could even get away with grana padano, though I’d expect a milder end product. But please please please don’t use the green-bottled ‘parmesan’ cheese. To be clear, there’s nothing wrong with a parmigiano-style cheese made by good cheese makers outside of Italy as long as you’re buying a large segment and shredding it yourself. The issue with the bottled stuff is that pre-shredding and packaging diminishes the complex and intense flavours of the original product (especially since the product can sit on the shelf for quite some time). I personally recommend staying away from the stuff altogether.
I dove into the issue of olive oil quality in this post about tuna crudo, but I’ll briefly cover it again here. Olive oil serves a vital role here, as it acts as a vehicle for the other flavours while contributing flavour of it’s own. Pretty much any olive oil will work in terms of emulsifying and carrying the flavours, but you want to give some thought to the character of the particular olive oil. Grassier/green-tasting oils are somewhat redundant given the greens used to make the pesto itself. Bold/spicy oils (some of which are also quite grassy) will overwhelm the final product, and can make the bite of the raw garlic seem too prominent. A milder, buttery olive oil is likely to yield the best results. There’s no need to break the bank though – an expensive certified Ligurian olive oil might be important to traditionalists (who, let’s face it, are not making radish green pesto), but as the Serious Eats article found, it won’t make a huge difference in the end.
The quantity of oil I use in this recipe reflects my taste for thick pesto. The picture at the top of this section gives a good sense of what I’m talking about. If you want a thinner sauce, add more oil (and, if you’re keeping track, bare in mind the added fat/calories that go along with it).
Weights vs. Volumes
As usual, I’ve tried to give a very detailed ingredient list, including multiple forms of measurement. I bring this up because, frankly, I can’t stand the way that most English-language pesto recipes are written. I know that a lot of home cooks in North America have an aversion to using a kitchen scale (though for the life of me, I don’t understand why – it makes everything WAY easier), but I simply cannot stand when I’m given ‘cups’ as a measurement for greens. It’s massively frustrating. In order to get a ‘cup’ of leaves, I have to clean and chop in batches or risk ending up with too much. On top of that, you’re forced to make a decision about just how much to pack a ‘packed’ cup of greens. Honestly, it’s just the worst system. And don’t even get me started on cheese – I mean, who wants to shred cheese INTO a cup measure, just to dump that into the recipe? So while I’ve included approximate cup measurements, I STRONGLY encourage you to buy a cheap-but-effective electronic kitchen scale and to use weights for this recipe. It’s easier, and you’ll have more consistent, repeatable results.
Food Processor vs. Mortar and Pestle
The Serious Eats article goes into pretty extensive detail on this subject, and I encourage you to read it in order to figure out what results you’ll get (and what you’d like to see).
The gist of the debate centers on the quality of pesto made with a food processor vs. one made with a mortar and pestle. Serious Eats came to the conclusion that you get a slightly better product using a mortar and pestle, and I think the results stand up to scrutiny. That being said, I used a food processor here for a variety of reasons, and I want to explain them so you can make your own decision.
First of all, as I mentioned above, I like a thicker, chunkier pesto. I always have. To that end, I actually let my food processor blade (not the grater attachment) chop my cheese along with the nuts, greens, and garlic. This yields a pesto with tiny little chunks of cheese that I personally adore. In terms of time, it’s probably something of a wash (the food processor is faster but takes longer to clean up), but I can make pesto in the food processor with one hand while holding a hungry/curious toddler in the other. Admittedly not a concern for everyone, but it certainly helps me.
Lastly, I take a slightly different approach to food-processor pesto, and I THINK (but haven’t done the side-by-side comparison) that it yields a result that’s at least somewhat closer to the mortar and pestle version. In essence, I focus on chopping AND crushing the greens in the first stage, then I add liquids after the fact. Greens, nuts, and garlic all go into the food processor and get well-and-thoroughly obliterated. The movement of the nuts helps to crush the greens, and to my eye, everything gets crushed more without the lubricating/emulsifying action of the oil. Then I add the cheese and pulverize again (yielding those nice little bits of cheese I mentioned above). Because I don’t add pre-shredded cheese, the food processor works even harder, and seems to really crush things up a little more (but again, that’s based on my interpretation, and not a thorough experimental approach). After that, I add my lemon juice and olive oil. Olive oil shouldn’t go in at the beginning in any case, as bitter flavours can develop when EVOO is whirred in a food processor.
In any case, I’m very happy with the end product. If I want a good arm workout, I might go for the mortar and pestle approach, but 9 times out of 10, I prefer the food processor method. If you like a thinner, oilier pesto though, you’ll probably get marginally better results with the Serious Eats style pestle-pesto. That said, it’s also worth noting that radish greens are frequently a little more robust than basil leaves, and you’ll probably have to put a bit more muscle into crushing them by hand.
Batch Size and Leftovers
Unless you eat a LOT of pesto in one go, this recipes probably makes more than you’ll need. I like making extra because a) it uses up all of the radish greens, and b) I like having leftovers for a few days to eat with bread, etc. If your radishes have small greens, or you need to toss a lot of sub-par leaves, just reduce the size of your pesto batch accordingly. If you do make a full batch, you can store the leftovers by placing them in a narrow glass jar (I use small mason jars), covered by a thin layer of olive oil. For longer term storage, portion leftover pesto into an ice cube tray, then cover and freeze. Store the frozen cubes in a sealed plastic bag and reheat as needed for a quick-and-delicious addition to a meal.
On the subject of storage, leftovers, and no-waste cooking in general, be sure to check out the wonderful No Waste Food Challenge on Elizabeth’s Kitchen Diary for lots of wonderful tips, suggestions, and recipes like this one!
Note: Nutritional Information is given for a 1/6th portion of the total recipe (including radishes and pesto), and does NOT include pasta, bread, etc.
No ingredient pages have been written yet for any of the ingredients in this recipe. Like to see one? Let me know in the comments below or by email.
No pantry pages have been written yet for any of the ingredients in this recipe. Like to see one? Let me know in the comments below or by email.
Note that the pesto and radishes themselves are gluten-free, but you’ll have to serve this with a gluten-free pasta or bread to keep the final meal that way. Try polenta to keep things simple, tasty, and gluten-free!
Roasted Radishes with Radish Green Pistachio Pesto
- 325 g radishes (1 large bunch, weight excluding greens)
- 1.5 tbsp olive oil
- 75 g radish greens and stems (~2 packed cups)
- 40 g Italian parsley (~1 packed cup)
- 40 g pecorino romano (or pecorino sardo) - see note
- 40 g parmigiano-reggiano cheese
- 3 cloves garlic (~10 g)
- 75 g pistachios (1/2 cup)
- 1 tbsp lemon juice
- 3/4 cup olive oil or more/less depending on the desired consistency
- salt to taste
- long pasta or bread to serve (feel free to substitute)
- Place a heavy, dark baking tray or large cast iron pan in the oven. Preheat the oven to 450 F.
- (Optional - if serving pasta) Bring a large pot of salted water to a boil on the stovetop. Once the water reaches a rolling boil, add the dried pasta and cook until al dente, per the instructions on the package.
- Separate the radish greens from the roots and set aside. Gently wash the radishes, then slice in half (from stem to root).
- Toss the radishes with the about 1.5 tbsp of olive oil, and a little salt and freshly ground pepper.
- Carefully remove the tray/pan from the oven (it will obviously be very hot). Working quickly, layer the radishes, cut-side down, onto the hot surfaces. Return the tray/pan to the oven and bake for 10-12 minutes, or until the radishes are browned, softened, and fairly wrinkled looking on the surface.
- Thoroughly wash the radish and parsley greens. Combine the greens, garlic, and pistachios in a food processor and puree. Scrape down the sides a few times and try to crush/chop the greens as thoroughly as possible.
- Once the greens/nuts/garlic are very well chopped, add the cheese. I add it in large pieces and let the blades do the work, which yields lots of little chunks of cheese (which I quite like). For a more uniform pesto, pre-shred the cheese.
- Once the ingredients are very well mixed, add the lemon juice and olive oil and puree again, until the mixture just combined and fairly smooth. Don't process too long, as the olive oil can become bitter. Add salt to taste and, if you like, extra olive oil and/or lemon juice.
- Serve the roasted radishes and pesto with the cooked pasta (if using), toast, fresh bread, polenta, couscous, or anything else you can think of that you'd enjoy.