Mornay Sauce
sauce veg
Makes 1 pint

Make up a Béchamel sauce as usual:
Put the milk in a pan with the onion, cloves and bay leaves and gently bring to the boil, then leave to infuse. If you can be bothered.
Melt the butter in a saucepan and stir in the flour with a wooden spoon until thoroughly combined, cook for a minute or two without browning.
Slowly add the strained hot milk, whisking constantly.
Return to the heat, bring the sauce to a simmer over a low heat and continue to cook for 2-3 minutes until it is smooth and thick.
If you want a thin sauce then use only ½oz of butter and flour.

Now turn this into a Mornay:
Add the Vermouth, and the mustard if you are using them don't overdo the Vermouth, then the cream a little at a time.
Remove from the heat and incorporate the cheese (to taste).
If you are also using the egg yolks, whisk them up with a little double cream and add them too.
Especially if you're going to be grilling this sauce over some fish.
Season with salt, white pepper and a grating of nutmeg.
You can, of course, use whatever cheese you like, but usually it would be a 50/50 mixture of Gruyère and Parmesan.
Just Gruyère would be acceptable.
I'm not sure just how much you can cook the sauce after you've added your cheese. Probably best not to.

Oh, I just felt like giving the quantities in as many forms as I could; here are some handy conversions for measuring small quantities of flour or butter for your Bechamel-type sauces: