Method

1. Using a mortar and pestle or a spice grinder, crush the mustard seeds and cardamom pods into a fine powder. If using a spice grinder, transfer the spices to a bowl.
2. Add the chile and garlic to the spices, and crush to form a paste.
3. Mix in the tamarind puree and turmeric then ½ cup of water to thin the paste and form a smooth sauce-like consistency.
4. Heat the mustard oil in a large heavy frying pan over medium-high heat.
5. Once the oil is almost smoking, reduce the heat to medium and add the onions. Sprinkle with some salt.
6. Sauté for 4 minutes, or until the onions are pale golden.
7. Add the cauliflower and fry for 6 minutes or until lightly browned.
8. Drizzle the spice mixture over the cauliflower and stir well to coat.
9. Bring to a boil then reduce the heat to medium-low.
10. Cover the pan and cook for 12 minutes, stirring occasionally, or until the cauliflower is nearly tender. To prevent the cauliflower from sticking to the pan as it cooks, add a little more water as needed.
11. Remove the lid and simmer uncovered, until the excess liquid evaporates and the mixture is dry.