In a large saucepan or soup pot with cover, combine stock, pickles, pickle liquid & potatoes. Bring to a boil, reduce heat and cook covered, over low heat until potatoes start to get soft (about 10 minutes).
Combine flour and milk, add to broth, bring to a boil and remove from heat.
Combine egg and butter and stir into broth.
Return pot to the stove and heat through without boiling. Season with salt and pepper. Garnish with sour cream and or dill.