Take a large pan, heat oil & fry cumin seeds, methi seeds, ginger & hing till it gets brown.
Then add Besan powder to the oil, stir continously till besan is golden brown.
Then add 4 cups of warm water. continue to stir till there is consistency in the liquid ( besan & water is mixed properly).
Then Add salt as per your taste, green chilly, tamarind, red chilly powder, turmeric powder to the liquid.
Let the liquid boil then add chopped vegetables & curry leaves.
Let it boil till vegetables are cooked & curry is of consistency (not very thick).
Serve it hot.