Preheat oven to 400 degrees. Spray a rimmed 18 by 13-inch baking sheet with non-stick cooking spray.
Place sweet potatoes and brussels sprouts on baking sheet. Drizzle with olive oil then to toss to evenly coat.
Sprinkle bacon over everything then roast in preheated oven 15 minutes. Remove from oven.
Add chicken, red onions, garlic and rosemary then season everything with salt and pepper and toss to evenly coat. Spread into an even layer (don't overlap chicken pieces).
Return to oven and roast until chicken has cooked through (center of thickest pieces should register 165) about 17 - 20 minutes longer.
Drizzle everything (or each serving) with balsamic glaze, sprinkle with parsley and serve immediately.
Recipe source: Cooking Classy
*Try to cut all of the chicken pieces close to the same size so they'll finish cooking through at the same time.