Method
 

1. Pre-heat oven to 190°C: 375°F: Gas 5

2. In a saucepan heat the butter, flour and milk together, bring to a boil, whisking continuously until thickened and smooth.

3. Simmer for a minute or two.

4. Remove from the heat and add the grated cheese.
   Stir until melted then beat in the egg yolks, allow to cool slightly.

5. Whisk the egg whites until stiff.

6. Carefully fold into the cheese mixture.

7. Pour into 6 buttered ramekins and bake for 30 minutes.

8. Serve immediately