Sardines are good for you as they are rich in omega-3s. This is a popular snack for teatime during my childhood. Instead of making sandwiches, you can also use this sardine recipe as filling for a savory pastry appetizer.
Mash the sardines until fine and mix in all the ingredients. Butter both sides of the bread. Spread the sardine mixture on one side of bread. Top it with cucumber slices and cover with another buttered slice of bread to make a sandwich. Remove crusts and cut the sandwich diagonally to make 4 triangles.