In a small bowl, combine buttermilk, egg, and hot sauce.
In a medium bowl, combine cornmeal, flour, and cajun seasoning.
Pat oysters dry with a paper towel. Dip oysters in buttermilk mixture, then coat with cornmeal mixture. Drop into oil 6-10 at a time, being careful not to crowd. Give the oil time to heat back up between batches.
Let oysters cook 2-3 minutes (depending on size) and pull out when golden brown. Put on paper towels to drain.
Assemble sandwiches with lettuce, tomatoes, oysters, and remoulade sauce.
Notes
Wild caught or farm raised oysters can be used.
It is important to not crowd the oysters in the pan when cooking. If necessary, cook them in batches.
Allow a few seconds between adding oysters to hot oil to allow time for the oil temperature to recover.