Directions

1. Melt butter in a saucepan and add flour. Cook for 2 minutes without browning, stirring all the time.
2. Gradually whisk in warm milk (using a whisk rather than a spoon). Continue whisking gently until sauce thickens, boils and is smooth.
3. Simmer sauce for about 2 minutes. It should eventually be quite thick and leave sides of pan clean.
4. Remove from heat and cool slightly. Beat in cheese, mustard, seasoning, Worcestershire sauce and egg yolks.
5. Beat egg whites to a stiff snow. Gently fold into sauce mixture with a large metal spoon.

6. Transfer to a greased 1.5 litre (2½ pint) Soufflé dish (or similar straight-sided, heatproof dish.)

7. Bake at 190°C/170°fan/Mark 5 for 50 minutes. It should be well risen and golden. It is vital not to open the oven door while the Soufflé is baking or it will collapse.

8. Remove from oven and serve immediately.