Sweet & savory chicken

For ➏
1.5-2 kg chicken
1 small lemon or clementine
several sprigs fresh rosemary
1-2 large yellow onions
3-4 whole firm fruits such as apples, pears, or quince
500-1000 g firm or crisp vegetables such as carrots, Brussels sprouts, potatoes, sweet potatoes, asparagus, mushrooms, or garlic cloves
olive oil
butter
sea salt & freshly ground black pepper

Heat the oven to 220°C. Set a rack in the lower-middle of the oven.
Remove the chicken from its packaging and thoroughly pat it dry. Place the lemon or clementine inside the cavity along with the whole rosemary sprigs, and truss the legs together.
Create a bed of fruits and vegetables in a roasting pan to raise the chicken off the bottom. Chop the onions and a few pieces of fruit into rings, and scatter them over the bottom of the pan. If you're using asparagus or carrots, lay them side-by-side on top of the onions in the center of the pan. Sprinkle the vegetables and fruit generously with salt and black pepper.
Set the chicken on top of the bed of fruits and vegetables. Roughly chop and scatter any remaining fruits and vegetables around the chicken.
Drizzle the chicken and all the fruits and vegetables with olive oil and sprinkle generously with sea salt. Set a few pats of butter atop the chicken.
Place the chicken into the oven and immediately lower the oven temperature to 200°C. Roast for 1 to 1½ h, until the vegetables are cooked, chicken's skin is golden, and the chicken registers 75°C in the thigh.
Transfer the chicken to a cutting board and tent with foil. Let the chicken rest for 15 m before carving.
While you're waiting, toss the vegetables with the pan juices and transfer to a serving bowl. If desired, make a simple gravy with the leftover bits in the pan.

Serve while the chicken and vegetables are warm.
Leftovers will keep refrigerated for up to 4 days.