This classic Russian dish is made with tender strips of beef, sautéed mushrooms, and a rich sour cream sauce. To make it, start by browning ground beef in a large skillet. Add sliced mushrooms and cook until they release their moisture. Then, stir in beef broth, Worcestershire sauce, and Dijon mustard. Simmer until the sauce thickens, then stir in sour cream and serve over egg noodles.