Preheat the oven to 180 ºC.
Place a baking sheet on the centre oven rack. Grease the base and sides of a 1,4 litre soufflé dish with margarine.
Separate the eggs into 2 bowls. Take care that no yolk gets in the egg white.
Melt the butter or margarine in a saucepan. Add the cake flour and heat, stirring continuously until the flour is cooked. Remove from heat and add the milk. Mix well until a smooth sauce is formed. Return to the stove and stir until the mixture begins to thicken. Remove from the heat, season with nutmeg, mustard, salt and pepper. Stir in the finely grated Cheddar cheese and allow the white sauce to cool for 5 minutes before stirring in the yolks. Set aside.
Beat the egg whites in a clean bowl until they are stiff but not dry. Stir about 25 ml of the stiffly beaten egg white into the white sauce to lighten the sauce slightly. Gently fold in the remaining egg whites, using a metal spoon.
Pour the mixture into the greased soufflé dish. Do not fill the bowl more than three quarters. Smooth the top slightly. Draw your finger around the inner rim of the soufflé dish so that the soufflé forms a 'hat' during the baking period. Sprinkle a little Parmesan cheese on top. Place the soufflé on the baking sheet in the oven and bake for 40 minutes.
Do not open the oven door while the soufflé is in the oven. Test to see whether the soufflé is done after the baking period has elapsed. Serve immediately with French bread and salad.
Recipe reprinted with permission of You