Melt 2 tablespoons butter in a large skillet over medium heat. Add chicken; brown on both sides, about 10 minutes. Remove from pan.

Add remaining 1 tablespoon butter, mushrooms and onion to pan; cook 3 minutes, stirring frequently.

Stir corn starch and wine in small bowl until smooth. Add milk, bouillon cube, parsley, mustard and thyme. Pour into skillet. Bring to boil over medium heat; boil 1 minute.

Return chicken to skillet. Cook 3 minutes or until heated. Serve with pasta or rice.