Heat a pot over medium heat and add the mustard seeds and cover. Cook until the mustard seeds start to pop.
Add the oil, cinnamon stick, cardamom pods, cloves, curry leaves and onion and sauté for about 5 mins until the onion are soft.
Then stir in the garlic and ginger, fry for 30 seconds followed by the rest of the spices and tomatoes. Mix well and let cook for up to 10 mins until it forms a fragrant and thick tomato paste.
Drain the rice and add it to the pot along with the water, season and mix.
From here you can do 2 things.
Either transfer the entire mixture to you rice cooker and cook until done.
Or leave in the pot, bring to the boil, reduce to a simmer, cover and cook for about 20 mins until done.
Fluff up the rice, top with some fresh herbs and serve by itself or with chutneys and curries.