Jules Alciatore created Oysters Rockefeller at Antoine's Restaurant in New Orleans in 1899 — named for John D. Rockefeller because the sauce was "as rich as Rockefeller." Antoine's has served the dish continuously for over 125 years and has never released the recipe. What is publicly known: the sauce is green, it does not contain spinach (Antoine's has stated this explicitly and repeatedly), and it is baked on the half shell until bubbling. The standard restaurant interpretation everywhere outside Antoine's uses spinach, which Antoine's considers incorrect. The most credible analyses of the original suggest a base of herbsaint (the New Orleans anise liqueur) or Pernod, green herbs (parsley, celery leaf, possibly watercress or green onion), butter, breadcrumbs, and no spinach whatsoever. The dish launched the global tradition of baked oysters on the half shell, and every variation since — Oysters Bienville, Oysters en Brochette, chargrilled oysters — owes its existence to Alciatore's 1899 invention.
Oysters on the half shell topped with a rich, green, herb-and-butter sauce, bedded on rock salt to hold the shells level, and baked or broiled until the sauce bubbles and the edges of the oyster just begin to curl. The sauce should be vivid green, intensely herbal, with a distinct anise note from herbsaint or Pernod, and rich enough that the butter pools around the oyster in the shell. The oyster itself should be barely cooked — still plump, still briny, the heat just setting the edges while the centre remains essentially raw.
Oysters Rockefeller is a first course — rich enough to announce a meal, not substantial enough to be the meal. Lemon wedges on the side to squeeze over. French bread to sop any sauce that pools on the rock salt around the shells. A cold, dry white wine or Champagne. The anise, herb, and butter richness need acid and bubbles to reset the palate between oysters.
1) The oyster must not overcook. Broil or bake at high heat (230°C+) for 4-6 minutes maximum — the sauce should bubble and the oyster's edges should curl slightly, but the centre should remain soft and translucent. An overcooked oyster is rubbery, shrunken, and has lost its brine. This is where the dish lives or dies. 2) The rock salt bed is functional, not decorative. It holds the shells level so the sauce and oyster liquor don't spill, and it retains heat to keep the oysters hot during the walk from oven to table. 3) The anise component — herbsaint (the New Orleans liqueur created in 1934 as a legal absinthe substitute) or Pernod — is structural. Without it, the sauce is herb butter. With it, the sauce is Rockefeller. A teaspoon per oyster is typical; the alcohol cooks off and leaves the anise flavour. 4) Breadcrumb topping — a thin layer of fine dried breadcrumbs over the sauce before baking creates a golden crust that provides textural contrast against the soft oyster and rich sauce beneath. The breadcrumbs should brown but not burn.
Shuck the oysters immediately before saucing and baking. An oyster that sits shucked for 20 minutes loses liquor, dries at the edges, and begins to taste flat. The assembly should be: shuck, sauce, salt bed, oven, table. Ten minutes start to finish. The sauce can be made ahead and refrigerated for up to two days. Cold sauce spooned onto fresh-shucked oysters actually works better — the cold sauce slows the oyster's cooking during the bake, keeping the centre more tender. Herbsaint vs Pernod: Herbsaint is the more traditional choice (it was invented in New Orleans specifically) and has a slightly drier, less sweet anise character than Pernod. Either works. Absinthe itself is the historically accurate spirit but contemporary versions vary wildly in quality. Chargrilled oysters — a modern New Orleans tradition from Drago's restaurant — take the Rockefeller principle in a different direction: oysters on the half shell grilled over open flame with garlic butter, Parmesan, and herbs. The char and the open flame produce a smokiness that Rockefeller doesn't have. Both traditions are alive and neither has replaced the other.
Using spinach — Antoine's has denied spinach for over a century. The internet is full of spinach-based "Oysters Rockefeller" recipes. They produce a different dish. The original's green colour comes from a combination of herbs (parsley, celery leaf, green onion, possibly watercress), not from spinach. Overbaking — the sauce needs heat; the oyster barely does. If the oyster has shrunk to half its raw size, it's overcooked. Speed is essential. Too much sauce — the oyster should not be drowned. A tablespoon of sauce per oyster is sufficient. The oyster's own brine is a flavour component; burying it under sauce eliminates that brine. Using small oysters — the dish requires a substantial oyster that can survive the brief baking. Gulf oysters (large, plump, moderate salinity) are the traditional choice. Small, intensely briny Atlantic oysters overcook too quickly.
John Folse — Encyclopedia of Cajun & Creole Cuisine; Tom Fitzmorris — New Orleans Food; Sara Roahen — Gumbo Tales