Heat the oil in a large pan.
Soften the chopped white onion for 5 minutes, then add the garlic, ginger and chilli flakes and cook another minute.
Stir in the turmeric, cumin and curry powder and cook 30 seconds until fragrant.
Add the rinsed lentils, coconut milk, stock, chopped cherry tomato and the whole cinnamon stick.
Bring to a simmer and cook 20–25 minutes, stirring now and then, until the lentils have collapsed and it's thick and creamy.
Add a splash more water if it tightens too much.
Season with salt and the lime, and fish out the cinnamon stick.
Heat the oil until properly hot, add the mustard seeds and wait for them to pop, then the sliced onion and fry until golden and crisping at the edges
Toss the salad ingredients together
Spoon the dahl into bowls and squeeze over lime juice.
Pour the sizzling tempering over the top, add a dollop of yoghurt, and the salad
