Preheat and prep the pan: Position a rack in the center of your oven and preheat to 425°F (220°C). High initial heat helps render fat quickly and jump-start browning for crisp skin; we'll lower the temperature after the first 15 minutes so the meat finishes evenly without drying.

Dry the chicken: Pat the whole chicken thoroughly inside and out with paper towels. Removing surface moisture is essential — a dry skin crisps in the oven instead of steaming.

Season under the skin: Gently loosen the skin over the breasts with your fingers (slide them between skin and meat) and rub about 1/2 tbsp of the olive oil and a pinch (about 1/2 tsp) of salt under the skin directly onto the breast meat. This flavors the meat and helps the skin brown from the inside out.

Stuff and truss: Stuff the cavity with 2 garlic cloves (crushed slightly) and one half of the lemon plus 2 sprigs of rosemary. Squeeze the remaining half lemon over the outside of the bird. Truss the legs with kitchen twine (tie them together) so the bird cooks evenly; if you prefer, you can skip trussing and roast spatchcocked for faster, even cooking.

Oil and season the exterior: Rub the outside of the chicken with the remaining 1 1/2 tbsp olive oil and season liberally with 1 1/2 tsp kosher salt and 1/2 tsp freshly ground black pepper. Rubbing oil over the skin promotes even browning; the salt helps dry and crisp the skin while seasoning the meat.

Prep the vegetables: In a large bowl, toss the parsnips, carrots and sweet potatoes with the last 1/2 tbsp olive oil, 1/2 tsp kosher salt, 1/2 tsp freshly ground black pepper and the remaining 2 sprigs of chopped rosemary. Cutting the veg into uniform 1-inch pieces ensures even roasting and caramelization.

Arrange in the pan: Spread the vegetables in a single layer in a large roasting pan or rimmed baking sheet. Set the chicken breast-side up on top of the vegetables (the veg act as a roasting rack and will soak up flavor from the drippings). Placing the chicken on the vegetables also prevents them from burning on the pan surface and results in a flavorful pan sauce.

Roast at high heat, then reduce: Roast the chicken at 425°F (220°C) for 15 minutes to encourage rapid browning and crisp skin. After 15 minutes, lower the oven to 375°F (190°C) and continue roasting for another 40–55 minutes, depending on size (see next step). The two-stage roasting gives you both a crisp exterior and a tender interior.

Check for doneness with an instant-read thermometer: Insert the thermometer into the thickest part of the thigh without touching bone. The USDA recommends 165°F (74°C). For the juiciest results, remove the chicken at 160–162°F (71–72°C) and let it rest — the carryover heat will bring it to 165°F while resting. This prevents overcooking and keeps the meat moist.

Finish and rest: When the chicken reaches the target temperature, remove the pan from the oven and tent the chicken loosely with foil. Let it rest for 12–15 minutes. Resting allows the juices to redistribute; carving immediately will cause them to run out and leave the meat dry.

Carve and serve: Transfer the chicken to a cutting board and carve (legs/thighs first, then breasts). Spoon the roasted vegetables and any pan juices onto a platter alongside the carved chicken. Taste the pan juices and season with a squeeze of the remaining lemon or a pinch of salt if needed.

Optional pan sauce (why): If you want a simple jus, place the roasting pan on the stovetop over medium heat, add 1/4 cup water or chicken stock, and scrape up the brown bits with a wooden spoon. Simmer 1–2 minutes to concentrate. This quick deglaze captures the browned flavors and adds a glossy finish to the plate.