Some restaurants get around this by frying the oyster and placing it on top of the sauce, already baked on its shell. This is an interesting and good idea, but it breaks up the dish into two disparate parts, and changes it pretty radically. The solution is to use more bread crumbs than looks or feels right. And to have the sauce fully cooked and hot before it goes into the oven, so that the dish can be cooked mostly by heat from above. Finally, as nice as oyster shells look, I think that from a taste perspective oysters Bienville and all the other baked oysters come out better when baked in a gratin dish.
Oysters are absolutely terrific right now.
Chances are you haven't had any good oysters Bienville in a long time. Below are some source and a recipe. This is a reminder that the anti-restaurant forces in the legislature have a pending batch of bills that will remove all speckled trout from restaurant menus, permanently. It will also take pompano and many other local species not only out of restaurants, but off your plate at home unless you're a fisherman. Please write your legislator.