Please note: this recipe calls for pre-cooked lentils to be added in step 6, so if you are using dried lentils you need to cook them until soft before starting this recipe - this is your first step (recipe times are calculated on the basis of the lentils already being cooked).
Begin by cutting the aubergine into large chunks and frying in 2 tablespoon oil until browned (5-8 minutes) - toss frequently. Remove from the pan and set aside.
Next, cut the onion in half. Chop one half into thick slices and dice the other half. Fry until softened (about 5 minutes).
Deseed and slice the peppers, add to the pan and fry for several minutes before adding the aubergine back in.
Peel the garlic cloves and ginger. Chop roughly and blitz along with the tomato puree and water using a stick blender.
Measure the herbs, spices and salt into the pan, stir for 1 minute until aromatic.
Add the liquid and black lentils and simmer for 20 minutes, stirring occasionally to prevent sticking. Add a little more water if the sauce gets too thick.
Quarter the tomatoes and drop into the pan. Cook for 10 more minutes. By then all vegetables should be tender and the gravy not to loose.
Once cooked, stir through the fresh coriander & yoghurt (if using), then serve with basmati rice or naan bread with a little extra yoghurt and coriander on top.