In a large skillet, saute mushrooms and onions in butter until tender
Remove and set aside. In the same skillet, cook the chicken until golden brown.
Add 1 cup of broth, wine (or additional broth), ketchup, garlic and salt. Bring to a boil. Reduce heat; cover and simmer for 15 minutes
Combine cornstarch and remaining 1/3 cup broth until smooth; stir into chicken mixture. Add reserved mushrooms. Bring to a boil; cook and stir for 2 minutes or until thickened. Reduce heat to low. Stir in sour cream; heat through, do not boil. Serve over egg noodles.