Prepare your oven by preheating it to 350°F/177°C/Gas 3

Prepare your gratin dish or shallow baking dish by lightly brushing it with butter.

Cook your cauliflower florets in slightly salted boiling water for about six minutes until just tender but not sloppy! You can also steam them if preferred for about ten minutes.

Now to make the sauce. Melt the butter in a heavy based saucepan over a low heat.

Add the flour and cook until golden.  Some people use a  wooden spoon for this - I prefer to use a balloon whisk and stir gently. This way I get no lumps! Stir constantly.

Pour in about half of the milk, stirring constantly to prevent lumps forming and it will be lovely and smooth.

Stir in the remaining milk,  then the bay leaf. Stir constantly.

Season with salt and pepper and nutmeg to your taste - literally, taste it at this stage.

Reduce the heat and simmer and stir for a few minutes.

Remove from the heat for the next part.

Remove the bay leaf.

Add the mustard and half of the grated cheese and stir until melted.

Place the cauliflower florets in your dish and pour over the cheese sauce  sprinkle the remainder of the cheese on top.

Bake for about fifteen to twenty minutes until golden brown.