Put the mustard seeds into a large non-stick pot and turn the heat up to high until the seeds start to pop. Once this happens add the onion and chillies. Sauté for three to four minutes until the onion is soft.
Add the ginger and garlic and sauté for a further minute. Add the tomatoes, turmeric, cumin and coriander. Sauté for a further four to five minutes.
Add the coconut milk and bring to a simmer and cook for a further five minutes. Remove the chillies and then add your veg and cook for a couple minutes. Add the chickpeas, tamarind, garam masala and coconut cream.
Taste, then adjust the seasoning, for instance you may need to add more tamarind or pepper.
Serve with brown rice.