In a large bowl, toss the chicken with the zest, half the scallions, 2 tablespoons oregano, 1 tablespoon oil, and ½ teaspoon each salt and pepper.
In another bowl, combine the tomatoes, olives, 2 tablespoons oil, the remaining scallions and oregano, ½ teaspoon salt, and ¼ teaspoon pepper.
Heat the remaining teaspoon of oil in a nonstick skillet over medium heat.
Add the chicken and cook until golden, 8 to 9 minutes per side. Add the orange juice during the last minute of cooking.
Meanwhile, cook the bulgur according to the package directions. Toss with the tomato mixture; serve with the chicken.