1In 12-inch skillet, melt butter over medium-high heat. Add beef strips, onion and garlic; cook 7 to 9 minutes or until beef is browned.
2In 3 1/2- to 4 1/2-quart slow cooker, mix beef mixture, soup, mushrooms, salt and pepper.
3Cover; cook on low heat setting 5 to 6 hours or until beef is tender.
4Stir cream cheese into beef mixture until melted. Stir in sour cream until well blended. Serve over noodles.