This simple method translates the regional ceremony of roasting South Carolina cluster oysters on a large metal slab over an open fire to the backyard grill. Just cover them with wet burlap or a wet, clean towel with no detergent smell. To serve, place multiple oyster knives and gloves on a table and encourage folks to shuck their own. Plan on at least 1 dozen oysters per person, and grill them in batches. Be sure to scrub and rinse oysters well before roasting; discard any with broken shells.