Spatchcock roast chicken with grapes
1 h 40 min
, each about 1 kg
, at room temperature
Position racks in centre and lower third of oven. Preheat to 375F. Have a large roasting pan and a rimmed baking sheet lined with parchment ready. Pat chickens very dry with paper towels. Place one, breast-side down, on a cutting board. Using sharp kitchen shears, cut along both sides of the backbone from end to end and remove. Flip chicken breast-side up, and open like a book. Press firmly on the breastbone with your palm to flatten. Repeat with other chicken.
Mix butter with salt and freshly ground pepper in a small bowl. Loosen skin of each chicken at neck-cavity end with a finger. Spread 1/2 tsp butter mixture under the skin, reaching in as far as possible. Gently push 2 or 3 sage leaves under skin on each side of breast, keeping leaves flat. Rub skin all over with remaining butter mixture.
Arrange chickens side by side on roasting pan. Slice heads of garlic in half horizontally. Place between chickens. Using a potato masher, gently mash half of grapes just until the skins burst, and scatter around chickens. Divide remaining grapes into 8 clusters and lay on prepared baking sheet.
Roast chickens in centre of oven until an instant-read thermometer inserted into the thickest part of the chicken reaches 165F, about 1 hour. Roast grape clusters in lower third of oven for 30 min. Transfer to a cooling rack. Transfer chickens to a cutting board. Cover with foil to keep warm. Remove garlic from pan. Pour mashed grapes and pan juices into a medium saucepan. Squeeze in garlic. Mash grapes and garlic into sauce. Bring to a boil, then reduce heat to medium. Gently boil, stirring frequently, until sauce is slightly reduced, 5 to 10 min. Skim excess fat from sauce. Cut chicken into 8 portions and serve with grape clusters and sauce.