The Diner’s Monte Cristo. (Deb Lindsey /For The Washington Post)

If the French croque monsieur and the American grilled cheese had a child, it would be the Monte Cristo: a sandwich filled with cheese and sliced meat, battered and often deep-fried. (It is American, after all.) The retro dish pops up now and then at diners, taverns and such chains as the Cheesecake Factory and Bennigan’s, where in March it was possible to win its “World Famous Monte Cristos” for a year.

According to the Oxford Encyclopedia of Food and Drink in America, the sandwich was first mentioned in 1923, in an American restaurant industry publication. While its origin story and the source of the name are unknown, historians generally agree that the dish comes from California. Despite its murky beginnings, the hefty sandwich continues to be popular, especially for brunch. When the Diner in Adams Morgan briefly took it off the menu, people demanded its return, says Wilfredo Canales, a manager at the 24/7 eatery.

1. Bread

According to a recipe in the 1949 “Brown Derby Cookbook,” three slices of white bread are to be used to make a double-decker sandwich. Locally, we’ve found it’s more common to use two slices and a single layer of filling. The Diner uses challah, while the Airedale on 14th Street NW makes the sandwich with sourdough. Slim’s Diner in Petworth uses a soft white bread from Lyon Bakery. In Virginia, Lost Dog Cafe stacks three layers in its Pound Hound, a sandwich inspired by the Monte Cristo. K Town Bistro in Kensington prefers whole grain.

2. Batter

You’re likely to find the sandwich battered and deep-fried, as at the Airedale (beer batter) and Slim’s (a “beerlike” batter, minus the beer). The Diner’s version is more like French toast, with challah coated in an egg batter and griddled. Lost Dog Cafe also uses layers of French toast.

3. Cheese

Swiss cheese is traditional, though cheddar, Monterey Jack and Gruyere are sometimes used. The Airedale boosts the filling with bechamel and whole-grain mustard; K Town Bistro adds a whole-grain mustard sauce, tomatoes and caramelized onions.

4. Meat

As with a croque monsieur, the meat of choice is sliced ham. Turkey is often added. (Swap in tongue as the meat — we assume beef tongue, but it’s not specified — and you’ve got a Monte Carlo, writes Helen Brown in her 1991 “West Coast Cook Book.”)

5. Sweet

Strawberry or raspberry jam is a typical accompaniment, for dipping. The Airedale serves its sandwich with a side of grape jelly, while the Diner keeps it in the realm of French toast with breakfast syrup. A dusting of confectioner’s sugar is another frequent addition.

Find the sandwich in the District at Slim’s Diner (4201 Georgia Ave. NW, 202-783-0699), the Airedale (3605 14th St. NW, 202-722-1212) and the Diner (2453 18th St. NW, 202-232-8800); in Virginia at Lost Dog Cafe in Alexandria, Arlington, Fairfax and McLean; and in Maryland on the lunch menu at K Town Bistro in Kensington (3784 Howard Ave., 301-933-1211).