Beef Stroganoff

1-1/2 pounds leftover rare or fresh steak

2 tablespoons butter

4 small onions, diced finely
1 cup sour cream
1 tablespoon catsup
1 teaspoon paprika
1 teaspoon Worcestershire sauce
pound fresh mushrooms, sliced
Salt & pepper to taste

Slice meat very thin. Melt butter in frying pan. Fry onions and meat in it for 5 minutes. Add remaining ingredients. Heat, while stirring, until piping hot, but not boiling (about 20 mins) Serve over egg noodles, garnish with parsley.