A yogurt-and-spice marinade does the real work here — cut deep into the chicken so it soaks all the way through, then roast hot for a charred, juicy result close to the real tandoor.
Grind the tandoori seasoning in mortar. Mix 2 tablespoons of the prepared spice mix with 2 tablespoons of yoghurt.
Using a sharp knife, make deep incisions in the surface of the chicken and gently rub the seasoning mixture deep into the flesh and under the skin of the bird.
Marinate the chicken in the refrigerator for at least an hour. Better it will be if you can keep it in the marinade overnight.
Set the oven on full heat.
Place the chicken in the baking dish, skin side up. Put the chicken in the oven, on the middle rack. Drop the heat on 180C.
Bake the tandoori chicken for just under an hour at 180C. The thighs will come out quicker, in about half an hour and the oven can be bit hotter; 210C degrees. The chicken should get a good colour and the skin needs to be crispy.
While cooking, brush with the sauce. Test for doneness at the end of cooking by poking a hole in the thick part of the meat. If the juices come out clear, the chicken is cooked.
Serve the Tandoori Chicken garnished with fresh coriander and lime.
Notes
Marinate overnight if you can — the flavor deepens noticeably compared to the one-hour minimum.
Cut deep incisions into the chicken before rubbing in the spice paste, so the marinade reaches the meat, not just the skin.
Chicken thighs cook faster than a whole bird — about 30 minutes at a slightly hotter 210°C.
Baste with the pan juices partway through cooking to keep the skin from drying out.
A hole poked into the thickest part of the meat is the simplest doneness test — clear juices mean it's ready.