Preheat oven to 180ºC (moderate). Grease a 2 litre casserole. Cook macaroni according to package directions. Melt fat in a large saucepan. Stir in flour, salt, paprika, and cayenne. Add milk. Cook over moderate heat, stirring until thickened. Remove from heat. Add cheese and stir until melted. Beat egg yolks until light. Fold into macaroni and cheese mixture. Pour into casserole. Bake for 35 to 40 minutes or until center is firm to the touch when pressed lightly. Serve immediately. Calories per 1 cup serving: About 300