Combine and mix lightly; bulgur, eggs, milk, onion, nutmeg, salt, Worcestershire Sauce and beef. Form into balls about 1 1/2 inches in diameter. Roll in flour. Heat butter in heavy skillet. Add meatballs and sauté over moderate heat until lightly browned on all sides. Remove to serving dish. Remove skillet from heat, blend into the drippings the flour, meat stock, sour cream. Heat, bring to a boil, stirring constantly. Pour over meatballs. Serve.