Wash the Belgian endives and slice them in half (in the length).

Prepare according to the instructions found at https://belgianfoodie.com/recipe/braised-belgian-endives/

Put the braised Belgian endives in a colander over a bowl and let drain excess liquid. Keep the liquid for later step.

Prepare 1 recipe of Mornay sauce according to the instructions found at https://belgianfoodie.com/recipe/mornay-sauce/.

Use a spatula to remove some of the excess liquid from the Belgian endives (with the little bits remaining) and add it to the Mornay sauce. Mix. Watch not to put too much liquid inside or else the Mornay sauce might become too thin.

Spoon some Mornay sauce on the bottom of your casserole dish so that it is about 2/3 covered.

Wrap each half of Belgian endive in a slice of baked ham. Wrap tightly without breaking the ham. Put each Belgian endive seam side down in a casserole dish. Depending on the size of the slice of ham (and how much you like ham) you might use a half slice for each half Belgian endive.

Continue wrapping each half of Belgian endive in the same way and place each rolled Belgian endive close beside the others. Continue in this way until all Belgian endives and ham are used. If you have too many Belgian endives or slices of ham, just add them to the casserole. A little extra of either ingredient won't hurt. You can prepare either 1 or 2 casseroles dishes. I often place 2 layers of rolled Belgian endives in a single casserole dish.

Spread some sauce on top of each layer of rolled Belgian endives. Sprinkle a little of the extra grated cheese on top of each layer of Belgian endives. Keep any extra sauce to serve with the mashed potatoes at the table.

Preheat oven to 200°C (375°F). Place the casserole dish(es) in top half of the oven. Cook about 40 minutes or until the top is lightly browned.

Serve the casserole of chicons au gratin with mashed potatoes and any remaining Mornay sauce.