Cut fresh salmon in small pieces suitable for serving, and fry in butter. Drain and keep warm. Add two tablespoonfuls of flour to the butter, in which the fish is cooked, and brown. Add two cupfuls of stock and cook until thick, stirring constantly. Take from the fire, add a tablespoonful of butter, a teaspoonful of minced parsley, and the juice of a lemon. Pour over the fish and serve.