- 4 (6-ounce) cans solid white tuna packed in water, drained
- 1/2 cup kalamata or other brine-cured black olives, pitted and minced
- 1/4 cup plus 1 tablespoon mayonnaise, plus more for spreading
- 1/4 cup finely chopped red onion
- 1 tablespoon plus 1 teaspoon capers, drained
- 1 tablespoon plus 1 teaspoon freshly ground black pepper
- 1 tablespoon fresh lemon juice
- 1/2 teaspoon salt
- 4 slices rustic white bread, or other dense white bread
- 2 medium tomatoes, sliced, or 8 tomato slices
- 4 ounces provolone cheese, thinly sliced
Preheat the broiler and position the oven rack about 6 inches from the broiler.
Combine the tuna, olives, mayonnaise, red onion, capers, black pepper, lemon juice, and salt in a medium bowl. Stir until well mixed.
Arrange the bread slices on a work surface. Lightly spread each slice of bread with additional mayonnaise and top with 2 tomato slices each. Divide the tuna salad evenly among the 4 bread slices over the tomatoes. Top the tuna salad with slices of provolone.
Place sandwiches on a sheet tray and place under broiler. Cook until cheese is golden and bubbly, about 5 minutes.