Drain the chana dal and grind to a fine paste.
Heat 30 ml ghee in a kadai and fry the sliced onions till brown and crisp.
Remove onions from the kadai with a slotted spoon.
In the remaining ghee add the turmeric, chilli and ginger pastes.
Fry for a couple of minutes.
Add the chana dal paste and fry, stirring frequently, until most of the moisture from the chana dal paste has evaporated.
Add the browned onions and salt to taste.
Mix thoroughly and continue frying for another five minutes.
The chana dal paste should have absorbed all the ghee in the pan and should be soft but should stick together in a lump or ball.
Place the chana dal paste on a plate and smooth down evenly to about one cm thickness.
While still hot, cut into square pieces.
Leave to cool and set, for about 20 minutes.
Heat the remaining 70 ml of ghee in a kadai or pan.
Fry the chana dal pieces or dhoka a few at a time until lightly browned.
Remove with a slotted spoon, draining off as much ghee as possible.
To prepare the dalna: For cooking the dalna, take two tablespoons of ghee from the remaining ghee left after frying the cubed dhokas.
Lightly fry the potatoes and keep aside.
Add the bay leaves and garam masala to the ghee.
Fry for a couple of minutes and add the masala pastes, salt and sugar to taste.
Fry for several minutes, adding water to form a gravy.
Stir and add the fried potatoes.
Simmer over medium heat until the potatoes are almost done.
Add the dhoka to the kadai in a single layer.
Spoon the gravy over the dhoka and continue cooking until the gravy has thickened.
Remove from heat and serve hot.