Preheat your oven to 400 degrees.
On a sheet pan, add the diced sweet potato, diced apple (no need to peel), and red onion. Set aside.
Make the apple cider glaze: in a small bowl, whisk together the apple cider, honey, mustard, red pepper flakes, and salt. (Reserve 2-3 Tbsp to glaze the chicken later.) Pour the remaining glaze over the potatoes, apple and onion on the pan and toss together. Sprinkle with seasoning salt. Bake the potatoes and vegetables for 20 minutes.
While the potatoes & apple cook, mix together the wet-rub for the chicken. In a small bowl, stir together the brown sugar, chili powder, garlic powder, salt, pepper and olive oil. Coat each chicken breast with the wet rub.
Once the potatoes have cooked for 20 minutes, remove from the oven. Place the chicken in the center of the pan with the vegetables and potatoes. Add the broccoli florets to the pan at this time as well. Pour the remaining apple cider glaze over the top of the chicken. Cook all ingredients for another 30 minutes at 400 degrees.
Chicken should be done after 30 minutes. Test with an instant read or meat thermometer - internal temp should be 165 degrees.
Remove from oven and let cool for 5-10 minutes before serving.