Mackerel and horseradish soufflé

Method

1. Preheat the oven to 180°C/fan160°C/gas 4. Grease 4 x 200ml ramekins with butter and set aside.
2. Melt 15g butter in a pan, then stir in the flour to form a paste. Slowly add the hot milk, stirring constantly to make a smooth sauce. Bubble for 2 minutes, then transfer to a large bowl to cool. Stir in the egg yolks, flaked mackerel, horseradish, chives and a little black pepper.
3. In a clean bowl, whisk the egg whites until stiff. Gently fold them into the soufflé mixture with a metal spoon. Spoon into the ramekins.
4. Put the ramekins in a deep roasting tin, then pour in hot water from the kettle until it comes halfway up the outsides of the ramekins. Put the tin in the oven and cook for 20 minutes until the soufflés are risen and golden. Serve immediately.