Melt the oil or ghee over a low to moderate heat and cook the onions until soft, then add the spring onions and garlic and continue to cook . Add the bay leaf, pepper, chillies, ginger, turmeric and salt.
Stir fry for a couple of minutes then add the potatoes and, stirring occasionally, saute for 10 minutes.
Add the remaining ingredients and 275 ml hot water. Cook gently for 15-20 minutes until all the vegetables are tender.