Wash thoroughly, boil, peel and cut sweet potatoes into cubes. Peel, wash and cut ginger into juliennes (very thin sticks).
Remove stems, wash and chop green chillies. Clean, wash and chop coriander leaves. Roast peanuts, de-skin and grind coarsely.
Mix together sweet potato cubes, tamarind pulp, cumin powder, green chillies, rock salt, peanuts and fresh coriander leaves. Garnish with ginger juliennes and serve.