Chopped Veggie Salad With Watermelon And Feta Cheese

Name: Chopped Veggie Salad With Watermelon And Feta Cheese
Ingredients: 1 pound Campari or plum tomatoes, diced, drained; 1 1/2 cup diced seeded watermelon; 1 large green bell pepper, seeded, cut into 1/3-inch cubes; 1 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, broken into small cubes (about 2 1/2 cups), divided; 2 green onions, chopped, divided; 1/4 cup thinly sliced fresh mint leaves, divided; 1/2 cup plain Greek-style yogurt; 1 teaspoon dried oregano