Swiss Chard and Gruyere Souffle
Preheat the oven to 200C/400F/Gas 6.
Butter a 1.5/2litre souffle or baking dish or 6 large individual ramekin dishes making sure all surfaces are well covered
Melt the butter in a medium saucepan, then add the flour and stir over a moderate heat for 2 minutes.
Gradually add the milk to the saucepan, stirring all the time, and let it just come to the boil.
Remove from the heat and add the mustard powder and then stir in the grated cheese,saving about 20g for the top of the souffle. Season with salt and pepper.
In a deep frying pan (I use a wok) heat the tablespoon of oil and fry the onion until soft and lightly brown. Add the washed and shredded chard to the onion in the pan and wilt down until soft.
Transfer the cooked spinach to the cheese sauce (or vice versa) and mix together well.
Separate the eggs and stir the egg yolks into the cheese and spinach sauce, mixing well.
Next whisk the egg whites until they are stiff, take a couple of spoonfuls and fold them into the sauce to slacken it off, now fold in the rest carefully.
Transfer the mixture into the buttered dish/es and sprinkle the remaining cheese on top. Allow room for the souffle to rise, so no more that 2/3rds full. (Unless you fancy making a baking paper collar and that's another story.)
Place on a baking sheet and bake for 15 minutes (individual ones) or 30 minutes if making one large soufflé.
Eat straight away.