Form sausage into 4 patties. Fry patties in skillet over medium heat until cooked & brown, about 5 minutes on each side. Drain on paper toweling. Heat oven to 190ºC . Mix sauerkraut, caraway seeds, brown sugar & mustard in small saucepan; heat until hot. Spread bagels with dressing, spoon half the sauerkraut on bagels; top with sausage patties, remaining sauerkraut & cheese. Wrap each bagel in aluminum foil. Bake 20 minutes. Unwrap; serve hot.