Mediterranean Tuna Antipasto Salad

2 5- to 6-ounce cans water-packed chunk light tuna, drained and flaked (see Note)

1 large red bell pepper, finely diced

1/2 cup finely chopped red onion

1/2 cup chopped fresh parsley, divided

4 teaspoons capers, rinsed

1 1/2 teaspoons finely chopped fresh rosemary

1/2 cup lemon juice, divided

4 tablespoons extra-virgin olive oil, divided Freshly ground pepper, to taste

1/4 teaspoon salt

8 cups mixed salad greens