About 24 hours before cooking (at least 6 hours before), place the chicken breast-down on a large cutting board with the wings facing you. Using sturdy kitchen shears, cut along the spine on both sides (through the small bones) to remove the backbone.

Next, turn the chicken over, place it on the board with its breast facing up and the breastbone towards you, and firmly press down on the breastbone to flatten it. Make small incisions in the skin on the wings so they stand out nicely when the chicken is lying down.

Pat the chicken dry all over with paper towels, place it on a wire rack on a baking sheet, and generously salt every inch on both sides. Then, place the chicken breast-side up on the rack, uncovered, in the refrigerator for at least 6 hours, ideally 24 hours.

Take the chicken out of the refrigerator about 30 minutes before cooking so it can warm up slightly. Then preheat the oven to 230°C (450°F). On a baking sheet with a wire rack, prepare a bed of coarsely chopped carrots, celery sticks, quartered onions, lemon slices, and, optionally, fresh herbs and a few peeled garlic cloves.

Lay the chicken flat on the bed of vegetables, using the vegetables to slightly raise the thighs so they are roughly level with the breast. Rub the breast with oil and season the chicken with pepper and spices of your choice.

Place the chicken, thigh-side down, in the preheated oven and cook for 40 to 65 minutes, until the internal breast temperature reaches approximately 68°C (155°F). (The exact cooking time depends on the size and weight of the chicken. A 1.3 kg (3.3 lb) chicken will be done in about 40 minutes, while a 2.5 kg (5 lb) chicken will need around 70 minutes. For the most accurate results, use a thermometer.)

Let the chicken rest for about 15 minutes after cooking, then carve and serve.