4 slices good, firm white bread such as Arnold Brick Oven or Pepperidge Farm
1/4 pound good ham (if you can get French ham, great; if not, black forest will do), sliced
6 ounces French or Swiss gruyere cheese , coarsely grated on a box grater
1-1/2 TBL butter
1-1/2 TBL flour
1/2 cup of milk (low fat or whole, it doesn't matter)
Salt and pepper to taste
Preheat oven to 400 degrees F.
Make the béchamel sauce (don't worry, it's easy, and almost foolproof):
Melt the butter in a saucepan over medium heat until foaming subsides. Add the flour and stir for about a minute.
Dump in all the milk and start whisking. Continue whisking more or less continuously for several minutes until the mixture starts to bubble and thicken. Reduce heat and cook, whisking for five minutes. If mixture doesn't thicken, turn heat up and cook some more. Season with salt and pepper and set aside to cool a bit.
Arrange 4 slices of bread on a a baking sheet covered with foil or parchment.
Spread béchamel over each slice, going right to the edge.
Top only 2 of the slices with ham
Distribute cheese over all 4 slices
Finally, place the two slices that don't have ham on top of the slices that do, cheese side up (that is, don't flip).
Bake until cheese is bubbling and just beginning to brown, about 10-15 minutes
Serve with French cornichons.