Cook the noodles following package directions. Drain in a colander and rinse with hot water. Set aside.
Meanwhile, in a large skillet over medium heat, heat the olive oil. Add the mushrooms and saute until browned and tender. Remove and set aside. Add the ground beef and onion to the skillet. Cook, stirring, until ground beef is no longer pink. Stir in the flour. Add the broth or water, the sauteed mushrooms, and the salt and pepper. Cook, stirring constantly, until hot and thickened. Stir in sour cream.
Serve the ground beef stroganoff mixture over the hot drained noodles.
Calories per serving: 421
Fat per serving: 16.8