These are delicious crisp cheesy puffs to have with a cocktail before dinner. Bake them at a really high temperature to make sure they rise well and go really crisp. Make a choux pastry using 150ml water, 50g butter, 60g plain flour, 2 eggs, a good pinch of cayenne pepper and half a teaspoon of mustard powder, and 60g grated Gruyere cheese. Melt the water and butter together and add the flour in one go. Beat really well over a low heat until the mixture forms a ball. Cool slightly, then beat in the beaten eggs, little by little. Finally, add all but 10g of the cheese, and the seasoning. Take generous heaped teaspoons of the mix and place on a non-stick or parchment-lined baking sheet, forming neatish mounds. Allow space for them to spread but it isn't disastrous if they meet and fuse whilst baking. Top with a little of the remaining cheese on each ball. Bake at 200C for 10 minutes, then turn the heat up to 220C for another 15 minutes. Now pierce the side of each puff to let the steam out and bake for another 5 minutes. Allow to cool for a few minutes and then devour! You can make them an hour or so in advance and reheat in a hot oven until crisp and golden again. These Burgundian treats, by the way, are traditionally eaten with Kir, either with still wine or 'Royale' with something bubbly.