- melted butter, for greasing
- 4 tbsp finely grated parmesan cheese
- 300ml/10fl oz milk
- 1 bay leaf
- 50g/2 oz butter
- 50g/2 oz plain flour
- 5 free-range eggs, separated
- 1 tsp Dijon mustard
- 2 tbsp chopped fresh tarragon leaves
- 100g/3½oz Gruyère cheese, grated
- Preheat the oven to 200C/390F/Gas 6.
- Brush the inside of a large soufflé dish with the melted butter and dust with the grated parmesan, shaking out any excess cheese.
- Bring the milk to the boil in a saucepan with the bay leaf, then remove from the heat and set aside.
- Melt the butter in a heavy-based saucepan and stir in the flour. Cook for 2-3 minutes, until the mixture turns a deep ivory colour and thickens. Pour in the warm milk, stirring or whisking until you have a smooth sauce that is free of lumps. Simmer gently, stirring from time to time, for about ten minutes.
- Remove the sauce from the heat and remove the bay leaf. Whisk in the egg yolks, one at a time, and stir in the mustard and tarragon leaves. Season with salt and freshly ground black pepper. Gently stir in the Gruyère, until melted and well combined.
- Beat the egg whites until soft peaks form when the whisk is removed from the bowl. Gently fold the egg whites into the cheese sauce with a large metal spoon, until just combined.
- Gently spoon the mixture into the buttered soufflé dish and bake in the oven for 25-30 minutes, until the soufflé has risen and is golden-brown on top.
- Remove from the oven and serve immediately.