1 15- to 19-ounce can beans, such as chickpeas, black-eyed peas or kidney beans, rinsed
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