Put all the pastes, black pepper, cumin, yoghurt, and vinegar in a large shallow dish. Season with salt and mix well.
Add the meat and rub evenly all over to coat. Cover and allow to marinate in the refrigerator overnight.
Prepare a tandoor or charcoal grill for moderate heat, or alternatively preheat the grill (broiler) to medium.
Put all the spices for sprinkling in a small bowl and mix together, then set aside.
Thread the meat onto several metal skewers and place a tray under them to collect any juices. Roast in a moderately hot tandoor, over a charcoal grill, or under the hot grill for about 10 minutes.
Remove the skewers from the heat and hang up to drain out any excess moisture. Put the skewers into a dish and baste with the melted butter, then roast for a further 5 minutes, or until cooked.
Sprinkle with the spice mixture just before serving.