Soak the lentils for 20 minutes. Drain and add 500ml (2 cups) water and boil until soft (add more water if necessary).
Heat the oil in a large saucepan. Add the cumin, mustard, fenugreek and fry for 2 minutes.
Add the tomato, carrots, okra. Chillies, aubergines, coriander leaves and tamarind.
Mix to combine. Stir for 5 minutes. Add the lentils and mix well. Add 500ml (2 cups) water and boil for 10 minutes or until the water is just about absorbed. Season with salt.