1.Blend or process onion, garlic, ginger and paste until smooth.
2.Heat ghee in large saucepan; cook onion mixture, stirring, 5 minutes. Add spices; cook, stirring, 2 minutes. Transfer to 4.5-litre (18-cup) slow cooker with chickpeas and the water. Cook, covered, on high, 2½ hours. Season to taste.
3.Serve sprinkled with coriander. Serve with steamed rice, yoghurt and naan (flat) bread.
To freeze: complete the recipe to the end of step 2. Pack into freezer-proof containers, leaving a 2.5cm (1 inch) space to allow for expansion. Seal, label and freeze for up to 3 months. Thaw overnight in the fridge. Reheat in a saucepan or microwave on medium power (50%) until heated through