- 1-1⁄4 cups béchamel sauce
- 1 12-inch short crust (made with 3 cups flour and 8 ounces unsweetened butter)
- 1 sheet puff pastry
- 8 ounces ham, sliced about 1⁄8-inch thick
- 1 large onion, sliced
- 4 ounces Comté, Citeaux or Epoisses cheese
- 1 egg yolk
- For béchamel sauce:
- 1-1⁄4 cups milk
- 1⁄2 cup veal stock
- 1⁄2 cup white wine
- 2 cloves chopped garlic
- 2 tablespoons chopped onions
- 1 tablespoon Dijon mustard
- 1 ounce flour
- 1 ounce unsweetened butter
A day ahead, make béchamel sauce. Combine all but the last two ingredients in a saucepan, and boil til the alcohol evaporates and the amount is reduced by about half. Roll flour and butter together into balls and whisk in to thicken. Refrigerate overnight. It should be the consistency of pudding.
To prepare the tart: Sauté onions in 1 teaspoon of butter til golden. Use the top of an 8- or 9-inch diameter, 3- to 4-inch-high cake or tart pan as a cookie cutter to cut a circle of the puff pastry; put aside. Cover the bottom and sides of the pan with the short crust, leaving about 1/2 inch hanging over the sides.
Layer one-quarter of the ham slices around the bottom of the crust. Add half the béchamel sauce, smoothing with a spoon. Top with another quarter of the sliced ham. Add the cheese to form one layer. Top with the sautéed onion, followed by another quarter of the ham slices. Add the rest of the bechamel, and top with the remaining ham.
Top with puff pastry, pinching the edges with the side crust. Glaze the top with beaten egg yolk. Bake in a 400Â° F oven for 45 minutes to 1 hour, or til nicely browned. Slice to serve.