Pat the chicken completely dry. Gently slide your fingers between the breast and the skin to loosen the skin and make two pockets. Repeat with the chicken thighs.
Place the chicken i a roasting pan and push pats of butter into each of the four pockets.Season generously with salt and pepper and drizzle with olive oil.
Arrange the grapes and thyme around the chicken. Add the lemon halves to the inside of the chicken then tie the legs together using butcher’s twine.
Roast the chicken until golden brown and internal temperature registers 165ºF (73.88ºC), about 1 hour. Remove the chicken to a cutting board to rest for about 10 minutes before carving.
Serve the chicken topped with the roasted grapes.
Notes
For the crispiest skin, make sure the chicken is thoroughly dried with paper towels before seasoning. If you have time, leave it uncovered on a rack in the refrigerator for several hours or overnight. This helps dry the surface of the skin so it browns more evenly in the oven.