Put the cumin and coriander seeds, cloves and black peppercorns in a dry frying pan over a medium heat. Cook for 1-2 minutes, stirring regularly until lightly toasted – you know they are ready when you can smell the spices.
Tip the toasted spices into a pestle and mortar or an electric spice grinder. Add the fenugreek, turmeric, paprika, chilli powder, cinnamon and salt to the warm, whole spices and grind them all into a fine powder.
Tip into a mixing bowl and stir in the garlic, ginger and yogurt. Mix thoroughly and leave to stand while the duck is prepared. Cut each of the duck breasts into 7-8 bite-sized pieces. Stir into the spiced yogurt, cover with cling film and put in the fridge to marinate for at least four hours, or ideally overnight.
Take the duck pieces from the fridge and skewer several chunks onto long metal skewers, keeping 1-2cm/½-¾in between each piece. You should be able to fit roughly five chunks of duck onto each skewer. (Chuck away any marinade that is not coating the duck.)
Preheat the grill to its hottest setting and place the skewers on a rack over a grill pan lined with foil. Slide onto a shelf as close as possible to the heat and cook for three minutes. Turn each skewer, holding with an oven cloth, and cook on the other side for a further 2-3 minutes, or until the duck is lightly charred on the outside but hot and juicy in the centre.
Hold the hot skewers with an oven cloth and use a fork to slide the duck tikka chunks off the skewers and divide among six plates. Add a salad garnish of fresh red onion rings and coriander. Serve with lime wedges for squeezing over the duck.