Put the urad dal on a Tawa or flat griddle or in a dry frying pan (skillet) and fry for about 1 minute, or until roasted. Transfer to a spice grinder and process until finely ground.
Put the rice flour on a Tawa or flat griddle or in a dry frying pan and cook for about 1 minute, or until roasted. Remove from the heat.
Put the cashew nuts into the spice grinder and process to a coarse powder.
Mix the ground ingredients together in a large dish. Season with salt.
Put the asafoetida in a small bowl, add 1 tablespoon water and stir until dissolved.
Heat the ghee in a pan, add the ground mixture and asafoetida mixture, and heat through.
Remove from the heat and put the mixture into a clean bowl. Knead into a dough, adding a little water, if necessary, then roll out on a lightly floured surface or board and cut into flat thin 3-cm / 1 1/4-inch rounds.
Heat the oil for deep-frying in a kadhai or deep, heavy-based pan to 180’C / 350’F, or until a cube of bread browns in 30 seconds.
Working in batches, deep-fry the rounds for about 2-3 minutes, or until golden brown. Remove with a slotted spoon and drain on kitchen paper (paper towels).
These biscuits (crackers) can be stored in an airtight container for 2-3 weeks.