In large skillet, brown ground beef and onion in butter.

Stir in flour, salt, pepper, garlic, and mushrooms. I chop up my mushrooms even smaller than they are before I add them. Cook 5 minutes, stirring constantly.

Stir in soup. Bring to a boil, then turn down and simmer, uncovered, for 10 minutes.

Stir in sour cream. Heat thoroughly.

Serve over wide noodles or rice. We prefer whole wheat wide noodles.