Oysters Bienville is a dish named after Jean-Baptiste Le Moyne, Sieur de Bienville (1680—1767), often called the “Father of New Orleans.” The oysters are covered in a mixture of shrimp, mushrooms, bell peppers, wine and a roux with butter. Arnaud’s restaurant created the dish to match the famous Oysters Rockefeller of Antoine’s restaurant.
   
“Bisque of Fresh Oysters Bienville” from the Maxwell House Coffee Shop as cited in the Nashville (TN) Tennessean on April 8, 1932. It is not certain if this “Oysters Bienville” was a different dish with the same name.
   
“Oysters Bienville” was cited as an Arnaud’s dish in a 1944 newspaper. 
   
   
Wikipedia: Oysters Bienville
Oysters Bienville is a traditional oyster dish in New Orleans cuisine. It is served at some of the city’s renowned restaurants, originating at Arnaud’s. Ingredients include shrimp, mushrooms, bell peppers, sherry, a roux with butter, Parmesan cheese and other lighter cheese, as well as bread crumbs. The oysters are baked in the shell or can be made in a small casserole dish or au gratin dish. This New Orleans dish of baked oysters in a shrimp sauce was named for Jean-Baptiste Le Moyne de Bienville (1680–1767), French governor of Louisiana and founder of New Orleans (1718).
   
Wikipedia: Arnaud’s
Arnaud’s is a well-known restaurant in New Orleans, Louisiana, United States. Arnaud’s is the largest restaurant in New Orleans, and also has the largest kitchen of any other restaurant in the city.[citation needed] Arnaud’s is among many restaurants that are located in the heart of the French Quarter, but it is only one of the few restaurants that fall under the category of serving classic Creole Cuisine. (...) Arnaud’s was founded in 1918, by a French wine salesman, Arnaud Cazenave.
   
Arnaud’s Restaurant
Oysters Bienville
*Serves 8 to 10*
 
1 tablespoon vegetable oil
2/3 cup finely chopped white mushrooms
4 tablespoons (2 ounces, ½ stick) unsalted butter
1-1/2 teaspoons very finely chopped garlic
4 large shallots, finely chopped
½ lb cooked shrimp, finely diced
1 tablespoon all-purpose flour
½ cup brandy
½ cup heavy cream
1 teaspoon ground white pepper
6 tablespoons grated Romano cheese
4 tablespoons dry breadcrumbs
¼ cup finely chopped flat-leaf parsley
1 teaspoon Kosher or sea salt
Freshly ground black pepper
½ teaspoon Cayenne pepper
2 dozen plump, salty, oysters, freshly shucked and the flat sides of the shells reserved
About 2 lbs rock salt (optional)
Lemon wedges wrapped in muslin sleeves, for serving
 
8 April 1932, Nashville (TN) Tennessean, pg. 19, col. 7 ad:
MAXWELL HOUSE COFFEE SHOP
(...)
Bisque of Fresh Oysters Bienville
 
6 February 1944, Detroit (MI) Sunday Times, “Famous Recipes From New Orleans,” pt. 3, pg. 9, col. 1:
... Oysters Bienville ...
(Listed under” Favorite Dishes” at Arnaud’s.—ed.)
 
4 October 1945, The Evening Sun (Baltimore, MD), “Wining and Dining In—New Orleans’s Vieux Carré” by Evans Rodgers, pg. 23, col. 5:
Arnaud’s is much younger (than Antoine’s—ed.), having been founded by Count Arnaud Cazenave shortly after he came to America only 25 years ago.
(...)
One night I ate with the Count from 8 o’clock until midnight…oysters Bienville, which are baked in a cheese sauce; ...
 
22 December 1946, Philadelphia (PA) Inquirer, “Mr. and Mrs. America Visit New Orleans” by Dick and Peggy Pollard, Everybody’s Weekly, pg. 18, col. 4:
Monsieur Arnaud Casanave, known informally as “Count Arnaud,” one of the real characters of New Orleans.
 
After we were finishing our first superb meal there (and we recommend “Oysters Bienville” and “Pompano Almondine”), our waiter came to tell us that the “Count” would join us in a few minutes.
 
3 December 1947, The Enquirer and News (Battle Creek, MI), “New Orleans Wonderful Food Dishes” by Edith M. Barber, pg. 20, cols. 4-5:
Oysters Bienville
36 oysters, in shells
1/2 cup finely minced green pepper
4 strips bacon, finely minced
2 tablespoons lemon juice
1/2 teaspoon pepper
Have oysters opened at market. Arrange on half shells in baking pan. Sprinkle each with green pepper. Bake in hot oven (450 degrees F.) about 10 minutes. Yield: 6 servings.
 
31 May 1948, New York (NY) Herald Tribune, “Cazenave-Conte 71; ‘Count’ of Arnaud’s: Opened His Restaurant in New Orleans in 1920.” pg. 14,col. 8:
The specialties of the house were oysters Bienville, the Count’s own version of New Orleans’ famous oysters Rockefeller; sauce Arnaud, and a drink called ambrosia concocted of applejack, champagne and lime juice.
   
1 April 1951, Orlando (FL) Sunday Sentinel-Star, “World’s Top Chefs Reveal Secret Recipes” by Cynthia Lowry (AP), pg. 34, cols. 1-2:
“Oysters Bienville of Jean Pierre of Arnaud’s Restaurant, New Orleans:
 
Bake 24 oysters on the half shell for 24 minutes under a moderate flame until they are half-cooked. Chop a bunch of shallots [or garlic soaked in water 24 hours] very fine and saute in butter until light brown. Add to this three tablespoonsful of flour, blending into the butter and then adding a cup of chicken broth. Allow this sauce to simmer for five minutes. Meanwhile, have prepared a pound and one-half of fresh, cooked shrimp and a small can of mushrooms, both diced fine, to which have been added the yolks of three eggs, a half pint of dry white wine, salt and a half-cup of sweet cream. Pour this mixture into the flour and butter sauce and cook slowly for 10 to 15 minutes when the sauce should be somewhat stiff. Remove from fire, pour over the oysters, sprinkle with bread crumbs and grated parmesan cheese. Return the hole under the broiler and remove when a golden brown.
 
The New Orleans Menu
Dozen Best Oysters Bienville
by Tom Fitzmorris | on March 10, 2014
(...)
No two recipes for oysters Bienville are exactly the same, but we can generalize a bit. They’re baked –usually on their shells, but sometimes in a small casserole–topped with a thick, stuffing-like sauce made with mushrooms, shrimp, bacon, green onions, a light roux and bread crumbs. The sauce usually makes up two-thirds or more of the dish. Named for the founder of New Orleans, oysters Bienville were introduced at Arnaud’s. Antoine’s claims that its chef came up with the idea, but felt that its Rockefellers already filled that slot, and so passed it along to Count Arnaud. (Arnaud’s denies this.)