Omelette Arnold Bennett with horseradish & chives

Method

1. Heat the milk and bay leaves in a medium saucepan over a medium-high heat. Once steaming, add the haddock pieces, cover with a lid and turn the heat down to very low. Poach the fish for 8 minutes, turning the haddock halfway, until cooked through. Remove the fish to a plate, reserving 150ml of the milk (discard the remaining milk).
2. Wipe out the saucepan with kitchen paper and add the 30g butter. Melt over a medium heat, then stir in the flour using a wooden spoon. Increase the heat slightly and let the mixture bubble gently, stirring constantly, until the colour darkens to a light brown and the mixture smells biscuity. Pour in the reserved milk in a thin, steady stream, stirring all the time, until the mixture thickens and it pulls away from the sides of the pan as you stir. If the mixture isn’t quite thick enough once all the milk has been added, cook it for a little longer until it has the right consistency. Leave to cool for a few minutes, then stir in the horseradish sauce, egg yolks, single cream and 25g parmesan. Flake the haddock (remove and discard any skin and bones), then stir in gently with some salt (if needed) and plenty of black pepper. Mix in the chopped herbs and set aside.
3. Heat the grill to high. Using an electric hand mixer or a balloon whisk, whisk the egg whites in a mixing bowl until they form medium peaks (the tops of the peaks created when the beaters are lifted out will flop over). Stir a spoonful of whisked egg white into the haddock mixture to loosen it, then use a large metal spoon to fold in the remaining egg whites in two additions, keeping as much of the air in as possible.
4. Melt the remaining knob of butter in the frying pan over a medium-high heat, swirling the pan to coat it evenly in butter. When it starts to sizzle, carefully tip the omelette mixture into the pan, tilting the pan so it covers the whole surface. Put the pan on the heat and cook for 3-4 minutes, shaking it every so often to keep the omelette loose. Once the edges have set, lift them up with the flat of a knife or a spatula to check the colour. When they’re light golden and the middle is beginning to swell and puff like a soufflé, scatter over a little more parmesan, transfer the pan to the grill and cook for 5-6 minutes until just golden, lightly crisp and puffed. Remove the pan from the grill (use a tea towel around the handle), slide the omelette onto a plate, cut in half and serve immediately.