Spiny Lobster Butter is 1 part cooked puréed lobster, blended with an equal amount of butter, then melted in a bain marie, then strained through a cloth into a bowl filled with iced water.
The melted, strained butter will congeal: collect it out of the water and put in on a cloth to dry.
It is use in sauces, soups and seafood stews.
For the cooked lobster, use the shell and trimmings of a spiny lobster, either cooked in a court bouillon or in a mirepoix.