1) Heat butter in a large skillet until it it foaming but not browned. Add chicken cubes.
2) Cook, stirring often, until chicken is firm and white - about 4 min. Do not overcook.
3) Add tomatoes and mushrooms to skillet. Cook and stir about 3 min.
4) Add the wine or broth to skillet. Increase heat and cook a few more minutes to reduce the sauce.
5) Stir in salt and pepper. Sprinkle with parsley;