Cut the cauliflower into florets about 25 mm across. Scrub and cut the potatoes into 15 mm slices (chip-like).
Heat the ghee in a frying pan or wok. When hot add the whole cumin seeds and then the chopped onion. Fry for about 5 minutes until golden brown and then add the ground turmeric, ground coriander seed and the chili powder.
Stir fry for 3 or 4 minutes then add the chopped tomatoes and the juice. Stir fry for another 3 or 4 minutes.
Add the potatoes and the warm water, cover and cook slowly for around 12 minutes (until the potatoes are half cooked). Add the cauliflower and cook for another 10 minutes. Stir in the peas, the chopped chilis, salt and garam masala. Stir well and add the sliced chilies.
Cook for another 5 minutes and then stir in the chopped coriander leaves before serving.