À l’armoricaine is French for "in the style of Armorica." With a velouté sauce with prawns, garlic, tomatoes and oil. Armoricaine is thought to be a corruption of américaine. The origin of homard à l’américaine is controversial, some claiming that it was invented by the chef Pierre Fraisse, a native of Languedoc who spent some time in United States. The one thing that is certain is that, containing such ingredients as oil and garlic, it is unlikely to originate from Armorica (the ancient name for Brittany).
