Treska is a traditional salad made with a combination of cod, mayonnaise, onions, carrots, vinegar, mustard, and seasonings. The cod is cooked in a mixture of vinegar, water, and bay leaves. It's then flaked and combined with cooked carrots and all the remaining ingredients.

The salad is left to chill in the refrigerator, ideally for at least 24 hours before serving. It's usually eaten with long Slovak bread rolls known as rožky on the side. The recipe for the commercial version of treska was created in 1954 by Július Boško, a chef from Nové Mesto nad Váhom.

It was ordered by Ryba, a company that was exporting fish to Slovakia and wanted to increase its popularity. Nowadays, treska is often made at home, but it can also be found in every supermarket.