This is a beautifully green soup in which you can make all kinds of substitutions such as broccoli for some or all the peas, watercress or spinach for some or all of the romaine and basil, dill or tarragon for some or all of the mint. The purslane adds and interesting crunchy lemony note and it’s a garden weed that can be foraged when it’s young and tender. This is a recipe from my book Cooking Wild.
3 tablespoons olive oil, divided
1/2 cup chopped green onions including green tops
2 teaspoons chopped garlic
3 cups fresh or thawed frozen sweet peas (about 12 ounces)
2 cups defatted chicken or shellfish stock
1-1/2 packed cups finely chopped romaine or other green lettuce
3 tablespoons chopped fresh mint
2/3 cup buttermilk, preferably labeled “Bulgarian” style
Drops of lemon juice and your favorite hot sauce, to taste
1 cup tender purslane leaves and stems
1/4 cup or so crème fraîche
Heat 2 tablespoons oil in a deep saucepan, add the green onions and garlic and sauté over moderate heat until softened but not brown, about 3 minutes. Add the peas and stock and bring to a simmer. Cook until peas are cooked through and tender. Remove from heat to cool for a few minutes. Add mixture to a blender and puree. Add romaine and mint and puree again until smooth. Add buttermilk and whiz again till combined. Season to your taste with salt, drops of lemon juice and hot pepper sauce. Strain through a medium mesh strainer and chill. Taste again for seasoning since chilling mutes flavor a bit.
To serve: Toss the purslane with the remaining tablespoon of olive oil and season with a little salt. Ladle soup into flat soup plates and top with purslane and squiggles of crème fraîche. Soup can be made up to a day ahead and stored covered in the refrigerator.
Note: If using fresh peas, you may want to add a little sugar depending on their maturity.