Wash and soak the dal in cold water overnight. Next day, strain and grind to a smooth paste.
Whisk into a batter with Â½ tsp. salt.
Make a very light butter-milk by mixing a cup of curd with 6 cups of water. Add salt (1 tsp), roasted cumin powder(2 tsp), Roasted red chili powder(1 tsp) and black salt(2 tsp), mix well and keep aside.
Heat oil in a pan. Drop one tbsp. of batter in flat round shape into Heated oil and fry until light golden.
Put fried bhallas into butter-milk and let them soak about 2 to 3 hours atleast.
Drain, squeezing out the butter-milk between the palms of your hands.
Whisk Yogurt well with sugar and salt to taste.
To serve, place the bhallas on a plate and cover with whisked yogurt.
Add Mint chutney and Tamarind chutney(these are optional).
Sprinkle red chili powder, black salt and roasted cumin powder. Garnish with coriander leaves.