Easy vegan moussaka

Put the aubergine slices in a large bowl and drizzle in 2 tbsp of the oil, season and toss well. Heat a large non-stick frying pan over a high heat and cook the aubergine slices, in batches, for 1 min on each side until charred and softening, then set aside on a plate. Heat the remaining oil in the frying pan and tip in the onion with a pinch of salt. Cook gently for 15 mins until softened, then add the garlic, oregano, cinnamon and cumin, and fry for a minute. Add the tomato purée and cook for another minute. Tip in the tomatoes and green lentils along with half a can of water, season and simmer for 15 mins until thickened.