Ham and Mushroom Crepes with Mornay Sauce

I FIND IT DIFFICULT to give set recipes for stuff ed crêpes, because to me they are perfectly designed for using leftovers and are an inspiration of the moment, not something for which you should go shopping. Easy to make and elegant to serve, they are ideal for the leftover lamb, turkey, or ham in your refrigerator. They can be eaten on the spot, of course, but you can also stuff, sauce, and store them for up to 2 days in the refrigerator or for a month, well wrapped, in the freezer.