Cut meat into cubes or thin strips. Melt 1/4 cup butter in large skillet/ Cook and stir mushrooms in butter about 5 minutes, remove mushrooms. In same skillet, brown meat. Reserving 2/3 cup of the broth, stir in remaining broth, the onion powder, catsup and garlic salt. Cover and simmer 30 minutes or until tender. Blend reserved broth and the flour, stir into the meat. Add mushrooms heat to boiling, stirring constantly. Boil and stir 1 minute. Stir in sour cream heat through but do not let boil. Cook noodles as directed on package, drain, toss with 3 tablespoons butter. Serve noodles with stroganoff poured over top.