How to make it
4 steps. Take it one step at a time.
Combine the drained tuna, mayonnaise, and chopped capers
In a medium bowl, combine the drained tuna, mayonnaise, and chopped capers. Mix well until a creamy, spreadable paste is formed. Season with a pinch of salt and pepper to taste.
Lay out the bread slices
Lay out the bread slices. If they have crusts, trim them off carefully to create perfect rectangles. Spread a very thin layer of mayonnaise on one side of each slice to act as a moisture barrier.
Mound the tuna filling
Mound the tuna filling in the center of two bread slices, leaving the edges slightly clearer but ensuring the center is thick. Place the remaining bread slices on top and press the edges down gently so the sandwich bulges in the middle.
Cut each sandwich diagonally from corner
Cut each sandwich diagonally from corner to corner to form two triangles. Serve immediately or wrap in a damp cloth to keep fresh.
A little kitchen wisdom
Traditional Venetian tramezzini are known for their 'dome' shape, where the filling is concentrated in the center. To keep them perfectly soft, wrap the finished sandwiches in a slightly damp, clean kitchen towel until ready to serve.
