Pan bagnat — Tuna and Egg Burgers

Ингредиенты

• 1/4 cup (60 ml) mayonnaise
• 2 tablespoons (30 ml) drained and finely chopped oil-packed pitted black olives
• 1 teaspoon (5 ml) capers, rinsed and finely chopped
• 1/2 teaspoon (2.5 ml) anchovy paste
• 1 lb (454 g) fresh tuna, finely chopped with a knife
• 4 kaiser rolls
• 4 eggs
• 2 tablespoons (30 ml) olive oil
• 1 tomato, thinly sliced
• 4 leaves Boston lettuce
• Salt and pepper