Dating back to at least 1673, ormer casserole is a Guernsey specialty made with ormers, pork belly, carrots, shallots, butter, and bay leaves. Ormers are a type of shellfish that is one of Guernsey's well-known local delicacies. They look similar to oysters and have a mild flavor.

Ormers can only be collected on a few dates between January and April, so this dish isn't always available in local restaurants. The ormers are removed from their shells, flattened with a mallet, then rolled in flour and fried in Guernsey butter.

Later on, they are combined with the other ingredients in a casserole dish, and the concoction is then baked until ready for consumption. It is recommended to serve this delicious casserole with crusty bread or Guernsey biscuits on the side.