Cook noodles in boiling salted water 5-6 minutes or until almost tender. Drain and set aside. Melt butter in a heavy nonstick skillet over medium low heat. Saut'e next 2 ingredients 4-5 minutes, stirring occasionally, until golden. Stir in beef. Increase heat to medium high and saut'e 4-5 minutes or until meat loses its pink color. Stir in next 5 ingredients and salt and pepper to taste. Simmer 15 minutes, uncovered. Stir in noodles. Cover pan and cook 5 minutes or until noodles are hot. Stir in sour cream and cook briefly until hot. Do not boil. Serve at once. Sprinkle with parsley for garnish.