METHOD
Preheat the oven to 200C/180C (fan), then butter a 1 litre soufflé dish and lightly dust the inside with a sprinkling of polenta, shaking out the excess.
Place the smoked haddock in a pan – you might need to cut it in half so it fits in snugly. Add the sliced onion and the bay leaf, then pour over the milk.
Cover the pan and bring to a gentle simmer, cook the fish for around a minute, then take the pan off the heat – the fish should be just cooked. If it isn’t, turn the fish over and leave it in the hot milk for a minute or two more until it is done. Lift the smoked haddock onto a plate to cool, strain off the milk and set aside.
Flake the Haddock from the skin, removing any bones you come across.
Set a saucepan over a medium heat and add the butter. When it’s bubbling away, work in the flour and cook, stirring regularly for a minute or so.
Gradually add the milk you set aside and whisk well, to achieve a smooth sauce.
When all the milk is added, let the sauce bubble gently, stirring often, for a minute or two. Fold in the cheddar cheese, mustard and chives and season well with black pepper. Let the mixture cool for five to ten minutes, then carefully fold in the egg yolks and the flaked, smoked haddock.
Finally, beat the egg whites until they hold soft peaks. Fold the egg whites, a spoonful at a time, through the mixture and try to keep everything as light and airy as possible.
Spoon the mixture into the soufflé, level it off, then place the soufflé in the centre of the hot oven to bake for 20 – 25 minutes., taking care not to open the door. When cooked, the soufflé should be well risen, golden on top and wobble gently when shaken. Serve immediately.