Put the oil in a large saucepan on a medium heat and, once hot, add the curry leaves, lemongrass and star anise and cook until the leaves crackle. Stir in the onion, cook for about six minutes, until soft and translucent, then add the garlic, cook for two minutes more.
Add the coriander, cumin, turmeric and chilli powder, stir to mix, then add the tomato puree, lentils and salt, and cook for two minutes.
Add the carrots and coconut milk, then fill up the empty coconut milk tin twice with tap water and add that to the pan, too. Cook, stirring occasionally, for about 20-25 minutes, until the dal is nice and thick and the carrots tender.
Stir through the tamarind paste, then taste and adjust the salt, chilli or tamarind as you see fit and serve topped with a spoonful of crispy chilli oil.
