First have a teacupful of warm water in a little pan. To it add 1 oz. of butter and a little pepper and salt, to boil a minute or two before adding enough flour to make it rather thicker than batter; never stop stirring a minute. It will be cooked enough if, taking a spoon, you can make the mixture come clean away from the sides of the pan.
It must then cool a little before working in 2 yolks of egg and a spoonful of grated Parmesan cheese, also 2 whites whipped stiff. Fill into baked cases of pastry and bake again.