Step #1 Clean & dry the chicken, leave the skin on.
Step #2 In a mixer or liquidizer, add in the sliced onion, ginger & garlic & grind to a fine paste.
Step #3 Pour the onion mixture into a bowl, yoghurt, lemon juice, & add in the rest of the ingredients - ground spices & salt, tomato puree & oil & give it all a thorough mix.
Step #4 I use the roasting tin that I cook the chicken in, line a roasting tin with foil wrap (makes washing up easier!), to marinade the chicken as well!
So, place the chicken in the roasting tin & pour the marinade onto the chicken & rub it in all over on the outside & the inside as well & cover the tin with another piece of foil wrap.
Step #5 Refrigerate for atleast 8 hrs but preferably over-night.
Step #6 Preheat the oven to gas mark 4/350F/180°C.
Step #7 Remove the chicken from the fridge & let it stand at about room temp for atleast 30-45 mins before cooking (on a warmer day, 30 mins will do).
Step #8 Place the chicken in the centre shelf of the oven for 1 hr, basting with the juices from the tin half way through.
Step #9 After 1 hr, take the foil wrap off & return the chicken back to the oven for another 20 mins basting every 10 mins to nicely brown & crisp up the skin.
Step #10 Remove the chicken from the oven & cover with foil wrap & leave it to rest for 20 mins before serving.