Preheat your oven to 400°F (200°C). Prepare a baking sheet or ovenproof skillet by lining it with parchment paper or lightly greasing it.
Pat the chicken breasts dry and season both sides generously with salt, pepper, and a pinch of cinnamon to enhance the warm flavors.
4 pieces boneless chicken breasts
Toss the cubed squash and halved Brussels sprouts with olive oil, minced garlic, sage, and a sprinkle of salt and pepper until evenly coated.
4 pieces boneless chicken breasts
Arrange the seasoned vegetables in a single layer on the prepared baking sheet and place the chicken breasts on top or alongside, ensuring space for even roasting.
Roast in the preheated oven for about 25-30 minutes, or until the chicken reaches an internal temperature of 165°F (74°C) and the vegetables are golden and caramelized.
Remove from the oven and let the chicken rest for 5 minutes, allowing juices to redistribute for a tender, juicy bite.
Slice the chicken breasts and serve alongside the roasted squash and Brussels sprouts, spooning any pan juices over the top for extra flavor.