Lobster Thermidor is a classic French lobster preparation that was very popular in upscale restaurants during the early to mid-1920’s.
In the dish, cooked pieces of lobster are mixed into a rich béchamel or heavy cream based sauce to which Dijon mustard, white wine, shallots, tarragon, lobster stock (for fish stock), and cheese, such as Gruyere or Parmesan. Mushrooms, truffles, or spinach are sometimes used, and there are many variations.
The lobster and sauce mixture is spooned back into the shells, whether the tail of American lobster or spiny lobster, topped with more cheese, and broiled to a golden brown.
Sometimes crab and shrimp are prepared in a Thermidor style.
How Was Lobster Thermidor Named?
The actual origins of the dish remain murky. However, there are two competing stores if how the dish was named. One of the most popular is that it was named by Napoleon. It is said he named it after the month he first at it. The month of Thermidor, according to the French Revolutionary calendar, was July 19 to August 17.
According to Lorousse Gastronomique, however, the dish was first prepared in 1894 at Maire’s Restaurant in Paris. The dish was named honor of the premiere of Victorien Sardou’s play, Thermidor, which was plahing at the theatre Comédie Française, near which the restaurant was located.
Lobster Thermidor is a very decadent and dish which seems simple. However, when served in restaurants it was (and is) quite expensive, not only because of the cost of lobster but because of the many steps required to make it. This is not to say it is difficult to make. It is simply time-consuming.