Optional but attractive: 10 to 12 fresh tarragon leaves blanched for 30 seconds in boiling water then rinsed in cold water, and dried on paper towels
Pour a spoonful of sauce over the chicken, and decorate the breast and legs with optional tarragon leaves. Platter may be garnished with sprigs of fresh parsley or—if you are serving them—sautéed potatoes and broiled tomatoes.
(*) AHEAD-OF-TIME NOTE:
If the chicken is not to be served for about half an hour, make the sauce except for its butter enrichment, and strain it into a saucepan. Return the chicken to the casserole. Place aluminum foil over it and set the cover askew. Keep the casserole warm over almost simmering water, or in the turned-off hot oven, its door ajar. Reheat and butter the sauce just before serving.