Once skinned and trimmed, slash the flesh on the legs twice, diagonally, down to the bone.
Blend the garlic, ginger, chilli in a pestle and mortar.
Place the chicken in a dish and stir in the blended ingredients. Pour on the lemon juice and the mustard oil
In a separate dish, mix the remaining ingredients (salt, garam masala, ground cumin seeds, Kashmiri red chilli powder, dried fenugreek leaves) with the yoghurt to create a paste. Add this yoghurt paste to the chicken and massage into the meat using your hands.
Cover, refrigerate and leave for at least 30 minutes, but the longer the better.
Transfer the marinated chicken onto the grill, and cook for about 20 minutes flipping halfway in