Dry roast the Bengal gram. Soak this for an hour then cook it.
Make soft dough out of wheat flour + water as needed + oil like you do for chapatti.
Boil and Cook the jack fruit. NOTE: don't use lot of water.
Grind cooked jack fruit, cooked Bengal gram, shredded coconut to a fine thick paste.
Melt the jaggery with little water and filter it. Now heat the filtered jaggery and add ground paste, cardamom powder and mix well until it get thick paste.
Now make small balls out of wheat dough. Coat banana leaf with little ghee and Flatten it as thin like papadum (applam). Now place little jaggery paste. Fold on all the side to cover the paste. Now roll it again gently.
Heat ghee in dosai skillet. Cook flattened "boil" like you cook chapatti in low heat and then serve.