|Chicken broth||55 Ounce (4 cans, 13 3/4 ounces each)|
|Frozen tiny peas||10 Ounce (1 package)|
|Leaf lettuce head||1⁄2 Pound, shredded|
|Chopped scallions||1⁄2 Cup (8 tbs)|
|Packed flat leaf parsley||1⁄2 Cup (8 tbs)|
|Unsalted butter||4 Tablespoon|
|All purpose flour||3 Tablespoon|
|Dry sherry||1⁄4 Cup (4 tbs)|
|Sour cream||1⁄2 Cup (8 tbs)|
|Freshly ground pepper||To Taste|
|Croutons||1⁄2 Cup (8 tbs)|
|Grated parmesan cheese||1 Tablespoon (for sprinkling)|
1. In a large heavy saucepan, combine the chicken broth, peas, lettuce, scallions and parsley. Bring to a boil over moderate heat. Reduce the heat to low and simmer for 15 minutes.
2. In a blender or food processor, puree the soup in batches until very smooth.
3. In a large saucepan, melt the butter over low heat. Add the flour and cook, stirring, for 2 to 3 minutes without letting the roux color. Whisk in the pureed soup and the sherry. Bring to a simmer over moderate heat. Cook for 5 minutes to blend the flavors. Remove from the heat. (The can be prepared to this point up to 1 day ahead. Let cool, cover and refrigerate. Reheat before proceeding.)
4. Stir the sour cream into the hot soup. Season with salt and pepper to taste. Serve topped with the Parmesan Croutons.