Soused fish

Back in the day, particularly in the 1970s, soused fish was extremely popular. According to The Guardian, it was once a common sight on restaurant menus across the United Kingdom, and while it may not be as common these days, it's simple to make at home. Mackerel is one of the most commonly soused types of fish, and it's made by simply boiling and simmering a vinegar-based liquid that typically includes peppercorns, bay leaves, and even juniper, as well as some onion and other veggies.

After simmering the liquid for 30 seconds to ensure that everything is incorporated, the fish fillets are added and simmered for another 30 seconds. The entire pot is then removed from the heat, refrigerated overnight, and served the next day. If you're looking for something unique to do with your fish, this could be the way to go.