I know it sounds seriously 1970's dinner party and it is a bit bit faffy to make but tastes seriously scrummy.
250ml (8 fl oz) milk 1 bay leaf 1/2 onion studded with a few cloves Salt & pepper 30g (1 oz) butter 2 tablespoons plain flour 6 eggs, separated 2 teaspoons wholegrain mustard 180g (6 oz) grated cheddar cheese
Pre-heat the oven to 180C/350F/Gas 4.
Pour the milk into a saucepan, add the bay leaf and the clove studded onion and bring to the boil. Remove from the heat, cover and leave to infuse for 20 minutes then strain and season with salt and pepper.
Melt the butter in a saucepan, add the flour and stir for one minute. Remove from the heat and gradually blend in the infused milk then put back on the heat and stir until it thickens (2-3 minutes). Leave to cool for 10 minutes.
Beat the egg yolks then stir them into the cooked white sauce. Add the mustard and nearly all of the cheese (leave about 1oz to sprinkle on the top) and mix together.
Whist the egg whites until the form firm but not dry peaks. Fold two tablespoons of the egg whites into the cheese mixture until combined then fold in the rest of the egg whites.
Lightly butter a large souffle dish (I used a casserole dish) and the pour in the egg and cheese mixture. Sprinkle the saved grated cheese on the top.
Bake in the oven for 30 minutes. Serve straight away.