1/2 pound Yukon gold potatoes
2 tablespoons grapeseed oil
1 cup diced onion
4 cups shelled sweet peas (about 4 pounds in pods)
6 cups vegetable stock, preferably homemade
2 to 3 tablespoons thinly sliced mint or Thai basil, plus more for garnish
1/2 teaspoon kosher salt
Freshly ground pepper, to taste
3 to 4 tablespoons softened unsalted butter

Cover the potatoes with a generous amount of water in a saucepan. Heat to a boil over medium-high heat. Reduce heat to medium and simmer briskly until potatoes are tender but not mushy, 20 minutes. Drain and set aside.

Meanwhile, heat the oil and onion in a large skillet over medium heat. Cook until onion caramelizes lightly, 8 to 10 minutes. Add the peas; cook until just cooked through, 5 to 6 minutes. (If using frozen peas, heat them just until hot.) Transfer onion and peas to a chilled baking sheet. Place them in freezer until peas are cold, 8 to 10 minutes.

Heat the stock to a simmer in a large saucepan over medium-high heat. Add onion, peas and potatoes; heat to a simmer until heated through. Process in a blender in batches until very smooth. Or use an immersion blender to puree soup directly in saucepan.)

Return soup to pot; add the mint or basil. Season with the salt and pepper to taste. Stir in the butter. Serve garnished with additional mint or basil leaves.

Makes 6 servings.

— Recipe adapted by the Chicago Tribune from "Sustainably Delicious: Making the World a Better Place, One Recipe at a Time," by Michel Nischan.