Rinse the lentils, then place in a large pot with enough cold water to cover. Bring to the boil, then reduce the heat, and simmer for 15-20 minutes, until soft, and the water has been absorbed.
While the lentils are cooking, heat the oil in a large pan (medium heat), add the cumin seeds, and allow to splutter for 30 seconds.
Add the onions, and sauté until they start to become translucent.
Stir in the turmeric, and continue to cook for another couple of minutes.
Pound the garlic, ginger, and green chilli together to make a paste, and add to the onions.
Fry for a few minutes, until the raw garlic and chilli smell has gone.
Mix in the tomato, curry powder, and garam masala and continue to fry, stirring occasionally, for another 10 minutes or so, until the oil separates out, and the paste comes away cleanly from the side of the pan.
If you want to have a smoother soup, now is the time to blend the veggies.
Reduce the heat, add the vegetable stock and the lentils, and simmer for 10 minutes.
Taste, and season with the salt and lime juice.
Add the coriander leaves, and serve with a few chilli flakes sprinkled on top, and a few grinds of black pepper.
This may seem like a lot of calories for a fasting day but if you're like me, and generally only have one meal on F-days, then it's perfect. With a 65g wholemeal roll, the meal comes to around 500 very filling calories.