Preheat the oven to 190°C. Brush the inside of 4 individual ramekins or one large soufflé dish well with some softened butter and refrigerate until needed.

Melt the butter in a saucepan and add the flour, stirring with a wooden spoon for 2 minutes to cook out the flour. Whisk in the hot milk and stir over low heat until you have a smooth, thick white sauce. This will take about 5 minutes. Add the mustard and the grated cheese and continue to cook until all the cheese has melted and there are no lumps left. Add the chopped chives, One for All and season with salt and pepper to taste.

Transfer the sauce to a bowl and allow to cool before whisking in the egg yolks one at a time.

In a clean bowl, whisk the egg whites to stiff peaks. Stir one large spoonful of egg whites into the cheese sauce to loosen it before carefully folding in the rest of the egg whites until it is all incorporated, taking care not to knock out too much air.

Fill the prepared ramekins all the way to the top with the souffle mixture, levelling the tops with the back of a knife. Run your thumb along the inner rim of the ramekin to create a clean line between the mixture and the rim – this is slightly messy, but it’s vital for successful rising.

Place the ramekins in a deep roasting tin and fill with hot water until halfway up the sides. Place in the oven on the middle shelf and cook for 10-15 minutes until they are well-risen and golden. Very carefully, but quickly, place the ramekins on to your serving plates and serve IMMEDIATELY!