A Mornay sauce is a Béchamel sauce with shredded or grated cheese added.

bbc.co.uk – crab_and_scallop_mornay

Usually, it is half Gruyère and half Parmesan, though variations use different combinations of Gruyère, Emmental, or white cheddar.

It is often served with seafood or vegetables.


  • 450 / 15fl oz. of milk
  • a few parsley stalks
  • 1 bay leaf
  • a pinch of nutmeg
  • 10 whole black peppercorns
  • 1/4 of an onion, sliced
  • 40g / 1 ½ oz butter
  • 20g / ¾ oz plain flour
  • salt and pepper, to taste
  • 50 g /2 oz grated cheese, such as Gruyere


  1. First place the milk in a small saucepan and add the parsley stalks, bay leaf, nutmeg, peppercorns and onion.
  2. Let it very slowly come to simmering. Then remove from the heat and strain the milk, and discard the flavourings.
  3. Melt the butter gently – don’t over-heat it or let it brown, this will affect the flavour of the sauce. As soon as the butter melts, add the flour and, over a medium heat and using a whisk, stir quite vigorously to make a smooth, glossy paste.
  4. Now begin adding the infused milk a little at a time – about 2 table spoons at first and stir again vigorously. When incorporated, add the a little more and continue adding each bit of liquid before you add the next. When half the milk is in, start adding large amounts of milk, but keeping whisking briskly.
  5. Now turn the heat down to its lowest setting and let the sauce cook for 5 minutes, stir from time to time.
  6. Stir in the cheese and whisk until melted. If the sauce seems to thick, thin with a little milk.
  7. Taste and season with salt and freshly milled black pepper.

If you wish to keep the sauce warm, either pour it into a thermos flask, or pour it into a warmed jug, cover the surface with cling film to stop a skin from forming, and place the jug in a pan of barely simmering water.