Soak the lentils in a bowl of water overnight.
The next day, drain the lentils, transfer them to a blender or food processor and process themto make a fine paste.
Put the paste in a clean bowl and mix in the bicarbonate of soda and asafeotida,then whisk the mixture until fluffy.
Mix the ginger, chillies, mint and raisins together in a bowl, then set aside.
Stretch a damp piece of muslin (cheesecloth) over the rim of a glass. Dampen the palms of your hands,shape the mixture into small balls, then flattenlightly on the muslin.
Heat enough oil or ghee for deep-frying in a kadhai or deep, heavy-based pan to 180'C / 350'F, or untila cube of bread browns in 30 seconds.
Place a smallamount of the ginger mixture in the centre and fold over to make a semicircle, using the muslin tohelp you, then gently press the edges to enclose the filling.
Using a metal spatula or slotted spoon, very carefully and gently slide each gujiya into the hot oil and deep-fry for about 3-4 minutes, or until pale golden.
Remove with a slotted spoon and drain on kitchen paper (paper towels). Make the others in the same way.
Put the deep-fried gujiyas in a bowl of warm, salted water and allow to stand for 10 minutes.
Meanwhile, to make the spicy yoghurt, put the cumin seeds in a dry frying pan (skillet) and roast for about 1 minute, or until fragrant, then transfer them toa mortar and pestle or spice grinder and pound orprocess until ground.
Whisk the yoghurt in a bowl, then stir in the roasted ground cumin and chillipowder. Season with salt.
Remove the gujias from the bowl and gently squeeze them with the palms of your hands to extract anyexcess water.
Arrange them in a serving bowl and pour the spicy yoghurt over the top. Serve with your choice of chutney.