Chicken Breasts in Mustard Sauce. Different types of mustard will make. Heat margarine in 10-inch skillet over medium heat. Add chicken breasts. Cook 12 to 14 minutes, turning after 6 minutes, until juices run clear. Remove chicken and reserve.Add onion and brandy to skillet. Heat to boiling; reduce heat. Stir in whipping cream, parsley and mustard. Cook and stir over medium heat 5 minutes. Add chicken and walnuts. Heat until hot. 4 Servings; 395 Calories Per Serving.