1 lg. ground beef chuck
3/4 tsp. salt
1/4 tsp. pepper
2 tsp. bottled steak sauce
1/4 c. dry bread crumbs
1 egg
2 tbsp. butter

SAUCE:

2 tbsp. butter
1/2 c. sliced onion
1/4 lb. mushrooms, sliced
2 tbsp. flour
1 tsp. catsup
1 can (10 1/2 oz.) condensed beef broth, undiluted
1 c. sour cream
Cooked rice or noodles

Make Meatballs: In large bowl, lightly toss ground beef with salt, pepper, steak sauce, bread crumbs and egg until well combined. Using hands, gently shape chuck mixture into 12 balls. In 2 tablespoons hot butter in large skillet, brown beef balls well all over. Remove beef balls.

Make Sauce: To drippings in skillet, add 2 tablespoons butter. Saute onion 5 minutes. Add mushrooms; saute 5 minutes longer, stirring. Remove from heat. Stir in flour and catsup. Gradually stir in broth; bring to boiling, stirring. Reduce heat and simmer, uncovered, 2 minutes. Add beef balls; simmer gently, uncovered, 10 minutes or until heated through. Stir in sour cream; heat gently over low heat. Serve over rice or noodles.