Beat the egg yolks with sugar until fluffy. Stir in flour and cornflour.
Beat the egg whites until stiff and fold into the mixture.
In a heavy ovenproof frypan heat plenty of butter. Pour the omelette mix over the butter and put the lid. Place the frypan into the hot oven. Reduce the temperature to 190 degrees C and bake until golden-yellow.
Remove from the oven and slide onto a heated plate. Fill with fruit compote or jam and fold.