Broccoli Souffle with Three Cheeses

First of all prepare the soufflé dish and its collar.

To do this, cut a piece of baking parchment 51 x 30 cm in length. Fold in half along its length so that it now measures 51 x 15 cm doubled. Now turn up a 2.5 cm fold all along the length to stabilise the base of the collar. Next butter the souffle dish really well and sprinkle the inside with some of the Parmesan, tipping the dish from side to side to give the base and sides a light coating. Empty out the excess, then tie the paper collar around the dish with the 2.5 cm folded bit at the bottom. The paper will overlap around the circumference by 7.5 cm and stand 5 cm above the rim of the dish. Fix the collar in place with string and tie with a bow so that when it comes out of the oven you can remove it quickly and easily. Now butter the inside of the paper and that's it – the dish is now ready.

To make the soufflé, sprinkle the broccoli with salt and steam over simmering water until tender – approximately 8-10 minutes. While the broccoli is cooking, prepare the eggs. Have ready a large bowl containing the extra egg whites and two small ones, separate the eggs into the small bowls one at a time, transferring the whites from the small bowl into the larger bowl as you go. When the broccoli is tender, remove it and leave to cool until barely warm. Then pop it into the processor and whiz it almost to a purée.

Next make the sauce.

Place the butter, flour and milk in a small saucepan and whisk with a balloon whisk over a medium heat until you have a smooth, glossy paste. Season to taste with salt and pepper, then season with the same amount again – this extra is really to season the large volume of eggs. Transfer to a mixing bowl and add the cayenne, nutmeg, Cheddar, Gruyère (or Emmental) and 1 tablespoon of the grated Parmesan. Add 3 of the egg yolks plus the broccoli and mix everything together.

Now the vital part – beating the egg whites.

Make sure the bowl and whisk are spanking clean, then wipe them with the lemon to ensure they're absolutely grease free. If you're using an electric whisk, switch it on to low and beat the whites for approximately 30 seconds or until they begin to start foaming.  Then increase the speed of the whisk to medium and then to high, moving the whisk round and round the bowl while it's beating until you get a smooth, glossy mixture that stands in stiff peaks when the whisk is removed from the bowl.  Click on our Cookery School Video to the right to watch how to do this.

It's better to underbeat than overbeat, so watch carefully. Next, using a large metal spoon, stir 1 tablespoon of the egg whites into the broccoli to lighten the mixture, then empty the broccoli mixture into the egg whites and fold, using cutting and turning movements, until everything is well amalgamated. Don't be tempted to do any mixing – it must be careful folding done as quickly as possible.

Now pour the mixture into the prepared dish, sprinkle the top with the remaining Parmesan and place on a shelf in the lower third of the oven (with no shelf above), for 40-45 minutes. When it's done it should be nicely browned on top, well risen and beginning to crack. It should feel springy in the centre but it's important not to overcook it, as it should be nice and moist inside because, as you are taking it from the oven to the table, and even as you are serving, it will go on cooking.

Divide between warm serving dishes and serve it absolutely immediately.