Preheat the oven to 200ºC/gas mark 6. In a medium bowl, whisk together the garlic, ginger, tomato paste, yogurt, garam masala, tandoori spice, salt and olive oil.
Rub the marinade all over the chicken, putting as much as possible underneath the skin. Place the chicken on a wire rack positioned over an tinfoil-lined baking tray (or roasting pan) and roast for 1 hour and 15 minutes. Check after 40 minutes, and if the chicken is browning too much, cover with tinfoil. Leave to rest for at least 10 minutes before carving, then serve.
It's All Easy: Delicious Weekday Recipes For The Super Busy Home Cook by Gwyneth Paltrow (Sphere, £20)