Lightly toast the coriander seeds in a frying pan to release the flavour, then crush them in a pestle and mortar.
Add the remaining spices and mix with the lamb, egg, lime juice and salt and pepper.
Form into 12 meatballs and thread 3 onto each of the wooden skewers. Bake in a hot oven for 30 minutes.
Mix the mango and yoghurt ingredients together and set aside.
Serve the spicy koftas on a warm plate with some of the yogurt dip and wedges of lemon.