Heat oven to 375°F.
Place the chicken in a small baking dish, coat on all sides with oil and season with salt and pepper. Pour the orange juice around the chicken. Cover and bake for 25 to 30 minutes or until the chicken reaches an internal temperature of 165°F and the juices run clear. Remove from the oven and set aside to cool slightly.
When cool enough to handle, cut the chicken into 1/2-inch cubes, cover and refrigerate until chilled.
Place the yogurt, orange juice, mustard, sumac, salt and pepper into a medium mixing bowl and whisk to combine. Add the celery, apple, bell pepper, golden raisins, parsley and cilantro, chilled chicken and toss to coat. Taste and add additional salt and pepper as desired.
Serve chicken salad on lettuce leaves.