Cut meat across the grain into 1/2-inch strips, about 1-1/2 inches long. |
Melt butter in large skillet. Add mushrooms and onion; cook and stir until onion is tender, then remove from skillet.
In the same skillet, cook meat until light brown. Add 2/3 cup of the broth, the catsup, garlic and salt. Cover and simmer for 15 minutes.
Cook the noodles per package instructions.
Blend reserved 1/3 cup of broth with flour and stir into meat mixture. Add mushrooms and onion. Heat to boiling, stirring constantly. Boil and stir for 1 minute.
Reduce heat. Stir in sour cream and maintain medium low heat. Serve over noodles.