1 large chicken, about 4 to 5 pounds (1.8 to 2.3kg)
2 tablespoons (30ml) light olive oil or other neutral-flavoured oil, such as canola or vegetable, divided
Salt and freshly ground black pepper (see note)
1 teaspoon (5g) baking powder (optional; see note)
2 teaspoons (10g) chopped fresh parsley, thyme, rosemary, oregano, marjoram, savoury, or a mix (optional)
1 medium onion, roughly chopped (about 1 cup)
1 medium carrot, peeled and roughly chopped (about 1/2 cup)
1 medium rib celery, roughly chopped (about 1/2 cup)
1 cup (240ml) dry vermouth or sherry
1 teaspoon (5ml) soy sauce
3 tablespoons (45g) unsalted butter
2 teaspoons (10ml) juice from 1 lemon
- Place oven rack in upper-middle position and preheat oven to 500°F (260°C). Using sharp kitchen shears, remove spine from chicken and cut spine into 5 to 6 one-inch-long pieces. Set spine aside. Flatten chicken by placing skin side up on a cutting board and applying firm pressure to breastbone.
- Transfer to a wire rack set in a foil-lined rimmed baking sheet. Position chicken so that breasts are aligned with the centre of the baking sheet and legs are close to the edge.
- Drizzle chicken with 1 tablespoon (15ml) oil. Combine 1 tablespoon (15g) salt, 1/2 teaspoon ground black pepper, and 1 teaspoon (5g) baking powder (if using) in a small bowl.
- Sprinkle all over the chicken. Sprinkle chicken with herbs, if using. Rub chicken to distribute seasoning evenly all over the skin.
- Roast chicken until thickest part of the breast close to bone registers 150°F (66°C) on an instant-read thermometer and joint between thighs and body registers at least 175°F (80°C), about 45 minutes, reducing heat to 450°F (232°C) if chicken starts to darken too quickly.
- Meanwhile, heat the remaining 1 tablespoon (15ml) oil in a small saucepan over high heat until shimmering. Add chicken spine and cook, stirring frequently, until well browned, about 3 minutes.
- Add onion, carrot, and celery and cook, stirring frequently, until beginning to brown, about 3 minutes.
- Add bay leaf and deglaze with vermouth or sherry and 1 cup (240ml) water, using a wooden spoon to scrape up any browned bits from the bottom of the pan.
- Reduce heat to maintain a simmer and cook for 20 minutes. Strain out solids and return liquid to pan. Boil over medium-high heat until approximately 1/3 cup (80ml) remains about 7 minutes.
- Whisk in soy sauce, butter, and lemon juice off heat. Season to taste with salt and pepper.
- Remove chicken from oven, transfer to a cutting board, tent loosely with foil, and allow to rest 5 minutes before carving.