Cook the potatoes in boiling salted water for 10-15 minutes until tender.Drain and allow to cool, then cut into cubes.
Heat the oil in a pan until very hot and add the mustard seeds.As soon as they pop, add the potatoes and chickpeas and stir to coat.
Stir in the ground Coriander, Chilli, Tomato puree and sugar and cover pan.
Cook gently for 5 minutes.
Serve Garnished with Coriander, accompanied with Boiled Rice.