mediterranean tuna antipasto salad

Ingredients:

• 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
• ½ cup finely chopped red onion
• ½ cup chopped fresh parsley, divided
• 4 teaspoons capers, rinsed
• 1 ½ teaspoons finely chopped fresh rosemary
• ½ cup lemon juice, divided
• 4 tablespoons extra-virgin olive oil, divided
• freshly ground pepper, to taste
• ¼ teaspoon salt
• 8 cups mixed salad greens