Preheat the oven to 180°C.
With your hands, rub the tikka paste all over the chicken making sure to get into the wing and leg crevices.
Wash the cauliflower, remove the stalk and roughly chop the florets. Place in a large roasting tray.
Wash the potatoes (no need to peel) and cut into similar sized chunks as the cauliflower. Add to the tray.
Peel the dudhi, slice into 2 cm rings and add to the tray.
Pour the vinegar and oil over the vegetables, together with the seasoning and half the coriander, finely chopped, then mix everything together thoroughly with your hands.
Pop the tray into the lower part of the oven then place the chicken straight on the bars of the shelf above it.
Cook for 1¼ hours, turning the vegetables a couple of times, then rest the chicken on them for a few minutes before serving with the remaining coriander scattered over.