Portugal is famous for its tinned fish, especially sardines, which are often sold in beautifully decorated tins, and it is home to Europe’s oldest cannery, Ramirez. I have Portuguese friends who happily eat sardines straight from the can as a mid-afternoon snack – really, this recipe is just a more delicious, slightly posher version of tinned sardines on toast, and it is often served as a starter in cafés and restaurants.