The most elegant versions of southern shellfish pies come from Maryland, where a puff pastry crust is filled with plump oysters and mushrooms in a cream sauce. Farther south, the dish becomes much less formal and more a casserole, with baked breads serving as a crust. The first recipe below comes from the Rappahannock River area of Virginia, where fine local oysters are especially prized. The shrimp pie is found in many variations from lower North Carolina through Florida.