A bounty of garden-fresh vegetables and loads of end-of-season basil means it’s time for soup au pistou, one of my favorite summer treats. The first time I made it, I was a bit confused by the simplicity of the ingredients: vegetables cooked in water, that’s it? I underestimated the transformative power of pistou, the French cousin of Italian pesto, very similar except without nuts (and in my version, without cheese either). In fact, the star of the soup is the pistou, pungent and a little sweet, melting into lightly cooked summer vegetables.
Some recipes call for pasta, some call for white beans, some call for both. I like to keep it pared down to the basics, truly just vegetables, water, herbs, olive oil, salt, and water. The long-cooked, complex flavors of stews and winter soups will be upon us soon enough – in these last days of summer, I’m still happy to keep things light and fresh.
Soupe au Pistou
Note: Dicing the vegetables into similarly-sized pieces ensures even cooking…and a prettier result. Substitute vegetables for what you have on hand or what looks good at the market. Consider green beans (a classic ingredient), peas or other freshly shelled legumes, turnips, radishes, asparagus, artichoke hearts, parsnips, mushrooms, etc. If you’re not avoiding dairy, freshly grated cheese, either mixed into the pistou or sprinkled on top of the soup, would be lovely. If you prefer a richer soup, you can cook the vegetables in a homemade meat or vegetable broth (a boxed or canned version wouldn’t work here).
For the soupe:
1/4 cup olive oil
1 cup leeks, white and pale green part, cut into 1/2-inch slices
1 cup red onion, cut into 1/2-inch dice
1 cup carrots, peeled and cut into 1/2-inch dice
1 cup kohlrabi, peeled and cut into 1/2-inch dice
1 cup patty-pan squash (or zucchini), cut into 1/2-inch dice
1 cup thinly sliced Savoy cabbage
1 teaspoon minced fresh thyme leaves
For the pistou:
1 fat clove garlic (or 2 small cloves), peeled and chopped
1 packed cup basil leaves, chopped
2 tablespoons olive oil
Make the soupe:
Set a heavy-bottomed Dutch oven over medium heat. Add the olive oil and when hot, add the leeks and onion with a pinch of salt. Saute, stirring frequently, until translucent, about 8 minutes. Add carrots and kohlrabi and another pinch of salt and continue sauteeing until carrots and kohlrabi are softening, 10 minutes. Adjust heat so vegetables are cooking and softening but not browning. Add squash, cabbage and thyme and saute another 5 minutes.
Add enough water to not quite cover vegetables and bring to a boil. Turn heat to low and simmer soupe, uncovered, until vegetables are just tender, about 10 minutes. Remove from heat and season with salt to taste.
Make the pistou:
While the soupe simmers, make the pistou. In the bowl of a mortar and pestle (or food processor), puree the garlic, then add the basil leaves and puree. Slowly add the olive oil until mixture is a paste. Season with salt to taste.
Divide soupe among four bowls. Swirl in dollops of pistou and serve immediately.