Beef Stroganoff

How to Cook Beef Stroganoff Ingredients: 1 lb. beef sirloin, sliced into thin pieces 1 piece onion, sliced 8 ounces button mushroom ½ cup sour cream 3 tablespoons cooking oil Salt and ground black pepper to taste 1 lb. egg noodles, cooked according to package instructions Roux ingredients: 2 tablespoons all-purpose flour 2 tablespoons butter 1 piece Knorr Beef Cube 2 cups water