2 tablespoons unsalted butter
3 cups coarsely chopped onion
Coarse salt and freshly ground pepper
4 cups vegetable broth
2 cups water
6 cups fresh peas
3 cups packed flat-leaf parsley leaves
1 cup packed mint leaves
2 tablespoons fresh lemon juice
1/4 cup crème fraiche, for garnish
Pea shoots, for garnish
Melt butter in a large pot uncovered over medium heat. Add onion and 2 teaspoons salt; cook, stirring occasionally, until onion is translucent, about 5 minutes.
Add broth and water; bring to a boil over high heat. Stir in peas and return to a boil. Remove from heat and stir in roughly chopped parsley and mint. Puree soup in a blender or using an immersion blender, until very smooth. Transfer to a clean bowl and stir in lemon juice. Season to taste with salt and pepper.
Chill soup in refrigerator for 1-2 hours or overnight. Serve in soup bowls and garnish with crème fraiche, and pea shoots.