Shrimps, often with other seafood such as haddock and anchovy, cooked, ground to a paste and potted with sweet spices and cayenne, sealed with clarified butter.

Original Receipt from 'Modern Cookery for Private Families' by Eliza Acton (Acton 1845);

POTTED SHRIMPS, OR PRAWNS. (Delicious.)
Let the fish be quite freshly boiled, shell them quickly, and just before they are put into the mortar, chop them a little with a verv sharp knife; pound them perfectly with a small quantity of fresh butter, mace, and cayenne.