Cream of Spinach Soup

Description
In Romanian: Supa de spanac (crema)

Ingredients

 * 3 qts/3 l water,
 * 1 lb/500 g spinach,
 * 1 lemon slice (with peel),
 * 1 tablespoon butter,
 * 1 teaspoon flour,
 * 1/2 cup sour cream,
 * salt,
 * French toast

Directions

 * 1) Wash and pick over the spinach. Set to boil with the water. After boiling for a little while, remove from heat and sieve everything.
 * 2) Set to boil again, adding the lemon, salt and butter. Let boil for another minute or two, then add the sour cream mixed with flour. Serve with French toast.