step 1
Place lentils in a pan and cover with 2 cups cold water. Bring to the boil, then reduce heat to low and simmer, stirring occasionally, for 15-20 minutes until thick and creamy. Cover and set aside.
step 2
Meanwhile, heat 1/4 cup oil in a large saucepan over medium heat, add cauliflower and half the cumin seeds and cook, stirring occasionally, for 2-3 minutes until lightly browned. Remove with a slotted spoon and set aside.
step 3
Add remaining 2 tbsp oil and cumin seeds to hot pan, then, as soon as seeds start to sizzle, add onion. Reduce heat to medium-low and cook, stirring occasionally, for 10 minutes or until onion is soft but not browned.
step 4
Add ginger, garlic and chilli, and cook for 2 minutes. Stir in ground coriander, ground cumin, turmeric, curry powder, coconut milk, cauliflower and tomato, then simmer, stirring occasionally, for 10 minutes or until cauliflower is just tender.
step 5
Stir lentils and lime juice into the curry and season to taste with salt. Simmer for a further 2-3 minutes, then stir in coriander. Remove from heat.
step 6
For the tarka, heat oil in a small frypan over medium heat, add spices and sizzle for a few seconds. Drizzle over the curry, cover and leave for 5 minutes for the flavours to infuse before serving.