Make a custard by mixing the egg yolks with 125g sugar, flour and cornflour. Pour boiling milk onto this mixture. Put back over heat and cook, stirring until boiling. Remove from heat and leave to cool. Heat 5cl cognac and blend into custard. Put egg whites until stiff, fold in remaining 175g sugar then fold into custard. Butter 6 ramekins, sprinkle with sugar, and lay grapes in the bottom. Add a spoonful of cognac then pour in custard.
Bake in the oven for 15 minutes at 200°C. Remove from oven and flambé at the table or mark out a pattern on the top of the soufflé with icing sugar.
Wine waiterâ€™s choice: 25 - 50 year old Cognac X.O. Floral notes with a hint of crystallised fruit and a slight taste of vanilla in the mouth.