6 knackwurst or 2 lbs. frankfurters
1 sm. finely chopped onion
1 tbsp. Dijon mustard
2 sm. sliced tomatoes
1/2 lb. finely chopped mushrooms
2 tbsp. butter
1/4 c. whipping cream
1 c. shredded Swiss cheese

Split sausages. Arrange in greased, shallow baking dish in single layer. Saute mushrooms and onion in butter over medium heat until brown. Smoothly mix in mustard and cream. Bring to a boil; cook, stirring occasionally, until liquid is reduced and slightly thickened. Divide mushroom mixture into split sausages. Top with sliced tomatoes, sprinkle with cheese. Bake, uncovered at 450 degrees for 15 to 20 minutes.