-
1
Chop leeks and in a bowl of cold water wash leeks well.
-
2
Lift leeks from water into a colander to drain.
-
3
In a large saucepan cook leeks in oil with salt and pepper, to taste, over moderately low heat, stirring, until softened.
-
4
Peel potatoes and cut into 1-inch cubes.
-
5
Add potatoes, broth, and 2 cups water to leeks and simmer, covered, about 10 minutes, or until potato is tender.
-
6
Stir in peas and simmer, uncovered, about 5 minutes, or until peas are tender.
-
7
While potato mixture is simmering, discard sorrel stems.
-
8
Cut leaves crosswise into thin strips (about 6 cups loosely packed).
-
9
In a blender puree potato mixture with sorrel in 4 batches until very smooth, transferring to a bowl.
-
10
Whisk in yogurt and 1 cup water, adding enough water to thin soup to desired consistency.
-
11
Just before serving, stir in lemon juice and salt and pepper to taste.
-
12
Garnish soup with egg and sorrel.
