1
trim the fat off the chicken.
2
cut the red bell pepper into strips and cut the red onion into slivers.
3
preheat oven to 450°F. Combine 1 teaspoon oil, five-spice powder, 1/2 teaspoon salt and 1/2 teaspoon pepper in a small bowl. rub the mixture into both sides of the chicken breasts.
4
heat 1 teaspoon oil in a large ovenproof nonstick skillet over medium-high heat. add chicken breasts; cook until browned on one side, 3 to 5 minutes. turn them over and transfer the pan to the oven.
5
roast until the chicken is just cooked through (an instant-read thermometer inserted into the center should read 165°F), 6 to 8 minutes. transfer the chicken to a cutting board; let rest for 5 minutes.
6
meanwhile, peel and segment two of the oranges (see Tip), collecting segments and any juice in a large bowl. (discard membranes, pith and skin.) add the greens, bell pepper and onion to the bowl.
7
zest and juice the remaining orange. place the zest and juice in a small bowl; whisk in vinegar, mustard, the remaining 4 teaspoons oil, remaining 1/2 teaspoon salt and freshly ground pepper to taste. pour the dressing over the salad; toss to combine. slice the chicken and serve on the salad.