Fresh green peas are at their sweet peak in New England just as spring makes her magical leap into summer. This elegant light potage allows the flavor of fresh peas to shine, but it works beautifully with frozen peas, too. We can imagine serving it outdoors under the trees, with candles on the table and little fairy-lights twinkling in the trees.

INGREDIENTS

4 tablespoons butter, preferably unsalted
1 medium onion, preferably a spring onion, chopped
4 cups shelled fresh peas or 2 10-ounce packages frozen peas
4 cups vegetable broth
½ cup dry white vermouth or white wine
¼ cup coarsely chopped fresh flat-leaf parsley, plus 2 small sprigs or leaves for garnish
1 teaspoon salt, or to taste
4 cups torn Boston lettuce
1 cup whole milk or half-and-half
½ teaspoon white pepper, or to taste
1/3 cup crème fraiche, plain yogurt, or lowfat sour cream, optional

1. Melt the butter in a large saucepan. Add the onion and cook over medium heat, stirring occasionally, until softened, about 5 minutes. Add the peas, broth, 2 cups of water, vermouth or wine, parsley, and salt. Bring to a boil, reduce the heat to medium-low, and cook, covered, for about 6 minutes, until the peas are about half cooked. Add the lettuce and continue to cook until the peas are completely tender, 4 to 8 minutes or more. (If using frozen peas, they will probably take a few minutes less to cook.)

2. Puree the soup in a blender or food processor, in batches if necessary, until smooth. Return to the saucepan, add the milk or half-and-half, and heat through. Season with white pepper and additional salt if necessary.

3.Ladle into bowls, top with a dollop of crème fraiche, if you like, and garnish with a parsley leaf.

Serves 6 to 8 as a first course, or 4 as a main course.