1.Heat oil in small frying pan. Stir onion, garlic and ginger over heat until onion softens. Add spices and chilli; continue stirring until fragrant.
2.Place onion mixture into 4.5-litre (18-cup) slow cooker. Stir in pumpkin, celery, lentils, chickpeas, undrained tomatoes, the water and stock. Cook, covered, on low, 6 hours. Season to taste.
3.Serve soup sprinkled with parsley.