2 tbsp. maple syrup
1 tbsp. balsamic vinegar
1 whole, pasture raised chicken (about 3 1⁄2 lb.)
Kosher salt and freshly ground pepper, to taste
2 tbsp. olive oil
1 tbsp. finely chopped fresh rosemary, plus 3 sprigs
4 cloves garlic, minced
3 small yellow onions, cut into 8 wedges
Heat oven to 450°. Combine maple syrup and balsamic vinegar and set aside. Season chicken inside and out with salt and pepper. Combine oil, rosemary, and garlic; rub the mixture all over the entire chicken, including under the skin on each side of the breast and thigh. Stuff half of the onions and rosemary into the cavity of the chicken.
Using a trussing needle and kitchen string, tuck tail inwards and truss cavity closed; tie legs together. Transfer chicken breast-side up to a 9” x 13” baking dish; cook, basting occasionally with pan juices, 40–45 minutes. Add remaining onion wedges and rosemary sprigs to pan. Brush chicken, onion, and rosemary with maple syrup mixture.
Continue to cook until browned and an instant-read thermometer inserted in the thickest part of thigh reads 165°, about 30 minutes more. Let chicken rest for at least 10 minutes before carving.