1 lg. onion
1 tbsp. butter
3/4 lb. ground beef
1/2 c. tomato paste
1 (4 oz.) can sliced mushrooms
1/2 c. diced celery
1/2 green pepper, diced
3/4 c. water
1/2 tsp. vinegar
Salt & pepper to taste
1 c. sharp cheese, diced
1/2 pkg. noodles

Cook onion in butter in large skillet soft; add ground beef. Brown. Stir in tomato paste, mushrooms, water, celery, green pepper, salt, pepper, vinegar and cheese. Simmer this mixture 15 minutes. Cook noodles according to package directions; drain, mix with sauce. Turn into baking dish. Bake, covered, at 350 degrees for 45 minutes.