Potted shrimps are a traditional English dish native to Lancaster, a port city on the northwestern coast. Historically, this dish was prepared as a preserved food that could be saved and eaten at any time, allowing people to enjoy seafood even when it was not available fresh. Today, people are more likely to eat it when it is fresh and using preservation techniques is less important. Some stores stock potted shrimps ready made for people to use, especially around Lancaster, and they are also very easy to prepare at home.
The original recipe calls for clarified butter, a butter that has been processed so that it will be stable at room temperature. The butter is seasoned, and then small or finely chopped shrimp are cooked in the seasoned butter and packed into a crock. The butter keeps air out, limiting the possibility of rot. The seasonings cover up some of the less pleasant odors and flavors associated with preserved fish. Potted shrimps were traditionally spread on bread or toast.
Modern recipes usually call for ordinary butter, although people certainly can use clarified butter; it can be prepared at home and some stores also stock it, sometimes labeled as ghee. The mace traditionally added to potted shrimps can be mixed with nutmeg, white pepper, paprika, and other spices to taste. Because the dish generally is not being preserved, ingredients like fresh parsley can be added as well. The shrimp are cooked in butter and packed into ramekins or pots for refrigeration. The potted shrimps will keep for several days in the fridge and they can be eaten with bread or added to other foods like omelets.
The original Lancastrian recipe for potted shrimps calls for brown shrimp, but any shrimp species can be used. The shrimp must be cleaned before use. Cooks who find cleaning and dejacketing shrimp tedious can usually find shrimp that are already prepared, often in the frozen section of a store or fishmonger's. It is also sometimes possible to buy fresh cleaned shrimp that are ready for use, as well as cleaned and precooked shrimp that can be used in the preparation of potted shrimp.
Some English restaurants offer this delicacy on their menus, sometimes with some creative variations on the original recipe. People can prepare or use this dish at home for entertaining or as a snack and some cooks enjoy playing with the original recipe to experiment with different spices and new ways to used potted shrimps in recipes.