4: Next add 50 g flour all at once, salt and pepper, then stir constantly for 1 minute using a soft spatula or wooden spatula. This mixture is the "roux" and should not be allowed to brown.
5: Still over low heat, pour in the hot milk in a trickle while whisking to mix thoroughly...
6: ...until the sauce is thick. If this looks familiar, it's because you have just made a classic bechamel sauce.
9: Check that the mixture is not too hot (you should be able to hold your finger in it); if not, leave to cool for a while longer. Then add the egg yolks 2 at a time, mixing thoroughly at each stage.
10: The mixture should now be very smooth. Preheat the oven to 360°F (180°C).
Here are the main points to watch if you want to make a successful soufflé: :
The roux must not be allowed to brown (don't overcook it)
The mixture must not be too hot when you add the egg yolks (or they will cook)
The whites must be beaten until they are quite stiff
The dish should be buttered well, then dusted with flour
The dish should have sloping sides (to allow the soufflé to swell and rise during cooking)
For a professional touch you can give the soufflé a flat, smooth top by smoothing the surface with a palette-knife before baking and begin the cooking with 3 minutes under the grill. As for the cheese, I prefer Comté, but you can use whatever you choose, even a mixture.