1Pat the chicken dry inside and out with paper towels—this is the secret to crispy skin.
2Heat your oven to 450°F.
3Cut one lemon in half. Stuff the cavity with both lemon halves, 3 sprigs of thyme, 2 sprigs of rosemary, 3 garlic cloves, and the halved onion.
4Set the chicken breast-side up in a roasting pan. Tuck the remaining garlic cloves around the bird.
5Rub the skin all over with olive oil, then season generously with salt and pepper. Arrange the remaining thyme and rosemary sprigs on top.
6Roast for 15 minutes at 450°F, then reduce heat to 375°F and continue roasting for 45–60 minutes, until an instant-read thermometer inserted into the thickest part of the thigh (not touching bone) reads 165°F. The skin should be deep golden brown.
7Remove the pan from the oven. Transfer the chicken to a cutting board and let rest for 10 minutes—this keeps the meat moist.
8Pour off most of the fat from the roasting pan, leaving about 1 tablespoon of drippings. Set the pan over medium heat on the stovetop.
9Juice the remaining lemon into the pan, add the stock, and scrape up all the browned bits from the bottom. Simmer for 2 minutes until slightly reduced. Season with a pinch of salt and pepper.
10Carve the chicken and serve with the pan sauce drizzled over each portion.