2 chicken breasts, diced (20-24 ounces)
4 tablespoons butter
1/2 cup chicken stock
1 medium onion, diced
8 ounces button mushrooms, sliced
1 cup Marsala wine
1/2 cup sour cream
2 tablespoons flour
salt and pepper to taste
Soak the chicken breasts in half the Marsala wine for around an hour, then brown in 2 tablespoons of butter and the Marsala used for soaking. Salt and pepper as needed.
When chicken is white in the center, remove chicken and set aside.
Add remaining butter and cook onions over medium heat, covered, until they are translucent. Add mushrooms and cook, covered, for several minutes. Stir in flour and cook for 4 minutes, uncovered. Add chicken stock and rest of the Marsala, increase heat to get sauce to boil and thicken. As soon as it starts to thicken, add the chicken back into the pan, cover and cook for 3-4 minutes. Stir in sour cream and cook for another minute.
Serve over toast, rice or noodles.