Steak and Mushroom Sauce -Katy

1 1/2 cup sliced mushrooms

1/2 cup sliced onion

1/2 cup chicken broth

salt and pepper

1/2 cup sour cream

1 Tbsp. flour

Season steaks as desired and cook on a skillet. Transfer to a plate and cover. Put a splash of vinegar on the drippings, then add the mushrooms, onion, and broth. Lower heat and simmer, uncovered, until onions are cooked. In a small bowl stir together the sour cream and flour. Stir this mixture into the mushroom mixture. Cook over moderate heat, stirring constantly, for 2 minutes or until thickened (do not boil). Spoon sauce over steaks.