Method

1. Put the onion, ginger, garlic, turmeric, cumin and a teaspoon of salt into the processor with 2 tablespoons of water, and process into paste. If you do not have a processor, or yours will not handle small quantities, grate the onion and chop the ginger, garlic and chillies as finely as you can. Mix the onion paste together with the ground turmeric, cumin and the remaining salt.

2. Heat 2 tablespoons of oil in a wide heavy-based saucepan. When hot, add the spice paste and fry, stirring constantly, for about 3 minutes.

3. Next add the potato and cauliflower to the pan, and stir until coated in the spice paste.

4. Pour in the remaining water and add the lemon juice, then bring to the boil. Reduce the heat to low, cover and cook gently for about 10-15 minutes, until the vegetables are tender but not collapsing, stirring once or twice.

5. Meanwhile heat the remaining oil in a small frying pan. Fry the cashew nuts until lightly browned.

6. Make the garam masala, by dry-frying the cumin, coriander, fennel, peppercorns and cardamom pods together in a heavy-based frying pan over a moderate heat until they smell aromatic. Cool slightly, mix with the bay leaf and the cinnamon, then grind to a powder in a coffee grinder or pestle and mortar. Reserve.

7. Check the water level in the saucepan when the vegetables are nearly done. If there is still a noticeable amount left, take off the lid and let most of it boil away. Now stir in the cashew nuts, and cook for a further minute or so. Taste for seasoning. Sprinkle with a teaspoon of garam masala and the chopped coriander, and serve at once.