chopped vegetable, watermelon and feta salad

INGREDIENTS

• 1 pound Campari or plum tomatoes, diced, drained
• 1 1/2 cups diced seeded watermelon
• 1 large green bell pepper, seeded, cut into 1/3-inch cubes
• 1/2 large English hothouse cucumber, seeded, cut into 1/3-inch cubes
• 1/2 cup very thinly sliced radishes
• 3 tablespoons olive oil, divided
• 10 ounces feta cheese, cut into small cubes (about 2 1/2 cups),
• 2 divided green onions, chopped, divided
• 1/4 cup thinly sliced fresh mint leaves, divided
• 1/2 cup plain Greek-style yogurt
• 1 teaspoon dried oregano