MELT BUTTER IN A SAUCEPAN OVER MEDIUM HEAT. WHISK IN FLOUR AND COOK FOR 2 MINUTES. GRADUALLY WHISK IN CHICKEN STOCK. REDUCE HEAT TO LOW AND COOK AND STIR UNTIL THICK ENOUGH TO COAT THE BACK OF A SPOON, 4-6 MINUTES. STIR IN HEAVY CREAM, AND SEASON WITH SALT, PEPPER, AND CAYENNE PEPPER.