It’s funny the things we self-taught home cooks take as gospel. Leek tops, for instance. How many times have I read a recipe that says, “1 leek, white and light green parts only?” That great dark green headdress gets lopped off first thing, and then what? Occasionally someone suggests saving the greens for the stockpot, but otherwise they go unmentioned and unused. This has led to more than one of my friends believing that leek greens are inedible.
So let it be known: The green parts are edible! Leek tops are just as flavorful and useful as the bulbs. They’re a bit more fibrous, but that’s easy to get around by cooking them long enough. And they’ve got the same delicate, almost sugary onion flavor as the bulbs.
If you’ve got allium issues, look to leek greens–like scallion tops and chives, they are low in FODMAPs. But unlike scallions and chives, they’re sturdy enough to saute or sweat, which makes them an easy substitute for onions or leek bulbs in a lot of dishes. Anywhere you’d start with a saute of aromatics–perhaps a mirepoix, or just a simple onion base–leek tops can provide. The flavor is milder than onions, and the greens mellow to a muted green color when cooked. For soups and stews, particularly, I find them indispensable.
Take this soup. I had zucchini that needed using, and this Serious Eats recipe on my mind. The recipe calls for one large leek, and I knew the green tops would work just as well as the white bottoms. So I sliced up the greens from one splendidly headdressed leek, and cooked them low and slow in a covered pan with some olive oil until they softened and turned jammy. Add some zucchini, fresh basil, water, and seasonings, simmer for a while, blend, and voila–a simple, summery soup that comes together surprisingly fast.
When it’s this hot out, and the summer produce is at its best, you don’t need to do much to your ingredients to make a great lunch. Zucchini and basil are a delightful combo, grassy and fragrant. The sauteed leek greens give the soup a sweet, aromatic backbone. A little olive oil for its smooth richness, and lemon juice for a fresh bite, plus salt and pepper, and that’s it. I like sipping pureed soup like this from a mug while I work, but you could easily dress it up in a bowl and serve it to guests.
This soup is great hot or cold, and I’ve been alternating between the two. Whichever you choose, try to season the soup at the same temperature you’ll serve it. So if you’re serving the soup cold, you can fine-tune a bit while it’s hot, but make sure to taste and adjust it again after it’s been thoroughly chilled. I split my batch of soup into individual freezer portions, and have been seasoning each portion according to how I feel that day. (Given the 100-plus-degree days we’ve been having lately, the cold version is especially satisfying.)
Five-Ingredient Zucchini-Basil Soup (serves 4)
Adapted slightly from Serious Eats
Green parts from 1 large leek, thoroughly washed
2 tbsp extra virgin olive oil, plus more for drizzling
1 1/2 lb zucchini (about 4-5 smallish zucchini)
Salt to taste (I used celery salt)
1 bunch basil (about 4 sprigs), leaves and stems separated
1 quart (4 cups) water
Juice of half a lemon (about 1 tbsp), or to taste
Freshly ground black pepper to taste
Thinly sliced the leek greens. In a medium saucepan, heat olive oil over medium-low heat. Add sliced leek greens and a large pinch of salt. Stir to combine, then cover and cook, stirring occasionally, for 10-12 minutes, or until the leek is soft.
Meanwhile, trim the zucchini and cut into 1/2-inch slices. Add sliced zucchini, basil stems, and water to the pot, and season with salt and pepper. Increase the heat to medium-high, bring to a boil, then reduce the heat to maintain a steady simmer. Cover and simmer for 10-12 minutes, until the zucchini is tender but still bright green.
While the soup simmers, roughly chop the basil leaves. When the zucchini is tender, remove the basil stems and add the leaves to the pot. Blend the soup completely smooth with an immersion blender, or in batches in a stand blender. If your blender is on the wimpy side–or if you just want an extra-smooth texture–strain the soup through a fine mesh strainer and discard the solids.
Season the soup with lemon juice, salt, and pepper to taste. Serve warm with a drizzle of extra virgin olive oil, or refrigerate and serve chilled.
Leftovers: The soup will keep in the fridge for up to 3 days, or in the freezer for 4-6 months. The color will darken a bit over time, but I think the flavor actually improves. Add a bit more chopped basil and lemon juice to the soup right before serving, to freshen the flavor back up.