Add cooking oil in to wok/kadai, under medium heat fry split black gram lentil, split chickpea lentil, coriander seeds, cumin seeds, fenugreek seeds, red chillies and curry leaves one after the other. Then grind all these roasted ingredients along with grated coconut to semi-fine paste. Add water as required to make thick paste.
Drain the water from raw banana cubes, add fresh water, turmeric powder and jaggery. Bring it to boil in medium flame and then cook it till soft in low flame. Include tamarind extract too.
Once the raw banana pieces are cooked well, add pressure cooked chickpea and pigeon pea lentils. Also include ground coconut+spices paste from step1. Mix well, add salt and water needed. Bring it to boil and switch off.
Heat a tempering pan, adding all the "seasoning ingredients" in the order mentioned, as the mustard seeds pop up transfer it to the raw banana curry.
Perfect side dish with rice,chapati is ready.