Mediterranean Tuna Sandwiches - cooking recipe

Ingredients

4 teaspoons roasted red pepper olive oil
4 teaspoons balsamic vinegar
8 slices whole grain bread or 8 slices pita bread
2 (6 ounce) cans tuna in water, drained and flaked
1/3 cup sun-dried tomato packed in oil, drained
1/4 cup ripe green olives or 1/4 cup ripe olives, sliced
1/4 cup red onions or 1/4 cup sweet Spanish onion, finely chopped
1/4 cup red bell pepper, finely chopped (optional)
3 tablespoons mayonnaise (optional) or 3 tablespoons low-fat mayonnaise (optional)
2 teaspoons capers (more to taste)
1/4 teaspoon fresh ground black pepper
4 romaine lettuce leaves or 4 curly green lettuce leaves

Preparation

Toast bread if desired.
Combine olive oil and vinegar in a small bowl; brush oil mixture evenly over 1 side of each bread slice or inside pita pockets.
Combine tuna and the rest of the ingredients (except lettuce).
Place 1 lettuce leaf on each of 4 bread slices.
Top the lettuce evenly with tuna mixture, and cover with remaining bread slices.
Serve immediately.