In a large skillet, heat the olive oil over medium heat. Add the diced onion and minced garlic, sautéing until the onion is translucent, about 3-4 minutes.
Season the chicken breasts with salt, pepper, dried thyme, and rosemary. Add the seasoned chicken to the skillet and sear on both sides until lightly browned, about 2-3 minutes per side. Remove the chicken and set aside.
In the same skillet, add the fresh or frozen cranberries, honey, and chicken broth. Bring to a gentle boil; then reduce heat and let simmer for about 5 minutes, allowing the cranberries to break down slightly.
Stir in the Brussels sprouts (or green beans) and grated butternut squash into the cranberry mixture. Add the cinnamon and stir well to combine.
In a large baking dish, place the chicken breasts at the bottom. Pour the cranberry and vegetable mixture over the top, ensuring the chicken is well-covered. If using walnuts, sprinkle them on top for added texture.
Cover the dish with aluminum foil and place it in the preheated oven. Bake for 25-30 minutes, or until the chicken is cooked through. Remove the foil during the last 10 minutes for a slight browning.
Remove the dish from the oven, let it rest for a few minutes, then garnish with fresh parsley before serving.
Notes
Serve with crusty bread or wild rice for a complete meal.