In skillet, cook sausage and onion until sausage is no longer pink. Remove from heat; add sauerkraut, cheese, 1 egg, flour, mustard and season to taste. Mix well. Roll into 1-inch balls. Place in freezer until partially frozen.
Combine milk and remaining 2 eggs. Coat each ball in egg mixture and roll in bread crumbs. In a large skillet, fry balls in 1/2-inch of hot oil for about 5 minutes or until golden brown.
Servings: 6