Cheddar and chive soufflé

Method

1. Heat the oven to 170°C fan/gas 5. Put a baking sheet in the bottom third of the oven to heat up (make sure there’s no rack above – it’s good to be optimistic about the rise of your soufflé). Grease the dish very generously with butter, dragging the butter upwards as you do so.
2. Mix the breadcrumbs and half the parmesan in a small bowl, then tip this into the buttered dish and shake it around so everything is well coated inside. Tap out any excess.
3. Melt the 50g butter in a small saucepan over a medium heat and, once melted, stir in the flour and mustard. Cook for a minute, then remove from the heat. Whisk in the milk, bit by bit, until all incorporated in a smooth sauce. Return to the heat, slightly lower than before, then stir with a wooden spoon until very thick and smooth (about 6 minutes) – it will be more like a paste than a sauce. Add the nutmeg, remove from the heat, then stir in the cheddar until melted. Scrape the mixture into a bowl, then beat in the egg yolks, one at a time (see Know-how). Stir in the chives, season with salt and pepper, then cover and set aside.
4. In a scrupulously clean bowl, whisk the egg whites until they form stiff peaks but are not dry. Add about a quarter of the egg whites to the cheese sauce and stir in well to lighten the mixture. Gently fold in the rest with a rubber spatula, drawing the mixture up from the bottom of the bowl and gently folding it over until it’s combined.
5. Spoon the mixture into the prepared dish. Gently smooth the top. Run the tip of a dinner knife around the edge – between the soufflé mix and the edge of the dish – then sprinkle the top with the remaining parmesan. Put on the oven sheet and bake for 20-25 minutes until the top is risen and golden – it should still have some wobble to it. Serve immediately.