Boil the chickpeas in water for about 30 minutes or until tender when pierced with a fork; drain well.
Beat the yoghurt together with ginger, chilli powder, cumin, coriander, rock salt or black salt, black pepper and salt. Set aside.
Season the mashed potato with salt.
Arrange crackers on a platter or plates. Place about 1 tablespoon of potato on each cracker. Place a few chickpeas on top of the potato. Spoon the spiced yoghurt on top. Spoon chutney on top. Garnish with the chopped onion, coriander and chip crumbs.
Serving tip: I like to set up a number of small bowls with each of the above condiments, so that each person can add whatever they want to, according to their taste and preferences.