A Monte Cristo sandwcih is like a stuffed, savory french toast. Similar to a Croque Madame, these sandwiches are typically filled with ham and cheese and then dipped in an egg batter before being pan fried. To make a kosher version, you can just leave out the ham and make a glorified grilled cheese, but I wanted to take that a step further and add in apple slices.
Everyone knows apples work well with cheddar, in my recipe I actually used a Blue Marble cheese from Sincerely Brigitte, but a cheddar would work well too. The apple didn't really get soft and I really enjoyed the crunch that it provided in this sandwich. While preparing this sandwich I learned that it is customary to serve a Monte Cristo sandwich with a sweet sauce, so I served mine with a Plum and Fennel Chutney I got from Kosher Artisanal. It went perfectly.
Here's my recipe for Apple and Cheddar Monte Cristo