1. Preheat oven to 425 degrees Fahrenheit. Prepare a sheet pan with Gefen Parchment Paper or nonstick spray.
2. In a mixing bowl, combine chicken, two tablespoons olive oil, rosemary, and garlic. Season chicken with salt and pepper to taste and mix well. Set aside while you prepare the vegetables.
3. Toss butternut squash, brussels sprouts, onion, and apple on the sheet pan with the remaining two tablespoons olive oil, and salt and pepper to taste. Toss with chicken pieces and spread chicken and vegetables into an even layer.
4. Roast for 20 minutes. Remove pan from the oven and toss well. Roast for another 15-20 minutes until chicken and vegetables are golden brown and cooked through.