We learned this method from Ben Moise, a longtime game warden and noted al fresco chef. To roast oysters the way they did in the old days:
1. Build a fire of oak and hickory, to get a hot ash. Put a steel plate over the fire and let it get hot.
2. Put the oysters in their shells on top of the steel plate. Cover them with a soaking wet croaker (burlap) bag. As the water drips down off the bag onto the plate it steams the oysters. It is important to keep the bag wet, otherwise it could catch fire.
3. When the oysters are done, shovel them directly onto a table and serve with Seafood Cocktail Sauce, hot pepper sauce, or simply "naked" (without any sauce).