Preheat oven to 375°F (190⁰C). Lightly grease a 13 x 9- inch (3 L) baking dish.
In a small bowl, combine mustard and mayonnaise; spread on one side of each baguette slice.
Place prepared baking dish on counter, with the shortest side facing you. Working from the top of dish, place 3 baguette slices (mustard side up), slightly propped up along the short side of the dish. Sprinkle with a ⅓ cup (75 mL) of cheese and top with 2 slices ham, overlapping (1 full slice per row). Prop the next slices of bread up against the ham and continue to layer until no ingredients remain. You should have 7 rows in total.
In a medium bowl, whisk eggs and milk. Add salt and pepper mix well. Pour evenly over contents in baking dish. Cover and refrigerate for 30 to 45 minutes.
Uncover and bake for 25 to 30 minutes or until golden brown. Serve hot with traditional Monte Cristo accompaniments, icing sugar and preserves, if desired.
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