Line a baking sheet with wax paper. Set up for what we call “standard breading procedure”: put the flour in a shallow bowl; put the eggs in a second shallow bowl and beat them with a fork; put the cracker meal, bread crumbs, cornmeal, and Old Bay in a third shallow bowl and whisk to combine.

Spread the oysters out on several layers of paper towels and blot them as dry as possible.

Heat about 3 inches of canola oil in a large saucepan over medium-high heat to 360°F.

Toss the oysters in the flour and shake off any excess. Dip the oysters into the egg, coating them completely. Lift them out by the handful and let any excess egg drip off, then place the oysters into the breading and toss to coat them completely.

Transfer the oysters to the baking sheet. To cut down on mess, keep one hand dry and use the other hand for wet. If the breading begins to clump, put it through a coarse sieve.

Fry the oysters in small batches—crowding the pan will lower the temperature of the oil and the oysters will come out greasy—until lightly browned and crisp, 1 to 2 minutes. Drain on paper towels.

TO MAKE THE SANDWICHES:

Split the ciabatta loaves and slather each cut side with about 1 tablespoon tartar sauce. Arrange 5 oysters on each sandwich, topping them with ¼ cup shredded lettuce. Put the tops on the sandwiches, slice them in half, and serve.

Note: If you can’t find cracker meal, you can make your own. Pulse saltine crackers in a food processor to very fine crumbs. Put the crumbs through a coarse strainer to remove any large pieces. An 8-ounce box of crackers will make about 2¼ cups of cracker meal.