Clean the lentils for any debris, rinse under cold running water, then put in a bowl, cover with 500ml cold water and set aside.
Heat a tablespoon of the oil over medium-high heat in a medium saucepan. Add the onions, and saute until they turn translucent – three to four minutes.
Add the carrots and pumpkin, and saute until tender – about eight minutes. Stir in the turmeric and red chilli powder, and cook for a further minute.
Add the lentils and their soaking water to the vegetables, stir in a teaspoon of salt and bring to a rolling boil over a medium-high heat.
Reduce the heat to low, cover and leave to simmer until the vegetables are completely tender and cooked – about 20 minutes. Remove from the heat, stir in the lime juice, taste and season with salt as needed.
Heat the remaining coconut oil in a small saucepan over a medium heat. When the oil is hot, add the coriander and mustard seeds, and cook until the seeds start to pop.
Add the ginger to the hot oil, cover the pan with a lid and swirl for 30 seconds, until the mustard seeds stop sputtering.
Break the Kashmiri chilli in half and toss it into the hot oil. Remove from the heat and swirl the contents of the saucepan for another 30 seconds, until the chilli turns crisp.
Pour this hot mixture over the lentils. Garnish with the fresh coriander leaves and serve warm with buttered flatbread or plain rice.