First Peel the raw bananas, cut it into half horizontally and then cut it into long vertical slices. Chop the tomatoes and coriander leaves. Grind ginger, garlic and green chilli into a fine paste by using some water. Grind Mustard Seeds into a fine paste by using some water.
Take a bowl, add gram flour, rice flour, ginger-garlic-green chilli paste, 1 tbsp turmeric powder, 1tbsp red chilli powder, 1 tbsp coriander powder, 1/2 black pepper powder, baking soda and salt into it. Mix it and add enough water to make a lumps free batter. Batter should not very thin nor very thick. Dip the banana fritters into the batter and coat it nicely with the batter.
Heat oil in a pan, drop these banana slices into the oil and deep fry it until it become golden brown and then take it out.
For curry, heat oil in a kadhai, add asafoetida, mustard seeds, fenugreek seeds into it, saute it and then add ginger-garlic-green chilli paste and mustard seeds paste into it, saute it for 2-3 minutes and then add turmeric powder, kashmiri red chilli powder, red chilli powder, coriander powder, black pepper powder, chaat masala and salt into it, mix it well and cook it on low-medium flame for 2 minutes and then add chopped tomatoes and coriander leaves into it. Cook it till tomatoes become little mussy and oil separates around the masalas.
Then add kasoori methi and 2 cups of water into it.Mix it and give it a boil and then add fried banana fritters into it. Cook it for 2 more minutes with the gravy on medium flame and then switch off the flame and serve it.