Vadas are savory lentil doughnuts that are made entirely with urad dal. You can eat with them as is with coconut chutney or sambar or both or even just plain old ketchup, but my mother-in-law serves them dipped in salty yogurt that is flavored with a paste of green chillies and coriander leaves. There’s a final tarka of mustard seeds, curry leaves, dried red chillies and green chillies added on the top. The spicy yogurt soaked dahi vadas are completely satisfying and delicious, and it’s easy to lose track of how many you are eating.
Soak about 2 cups of whole skinned urad dal overnight to make about 30 vadas
Discard soaking water and use a wet grinder or blender to grind the urad dal with minimal water to make the batter. Add salt to taste and keep aside for 15 minutes. Make round balls with your fingers or doughnuts if you are skilled enough, and begin frying on high heat. I am only able to manage round vadas that don't have a hole in the center. Keep a bowl of water on the side to keep your fingers clean of the moist batter in between dippings.
Frying away. Flip over when one side turns golden. Remove when both sides are golden brown. Turn down heat if the oil gets too hot, but the vadas usually cook well in medium-high heat.
Crisp, hot and ready to eat as is vadas, but keep on reading for dahi vadas
To make dahi vadas, at first, soak the vadas, a few at a time, in a mixture of lightly salted yogurt and water for a few seconds. Flip over and keep aside in a bowl.
Here are the soaked vadas. Now separately make a salty yogurt mixture that's been mixed with finely chopped coriander and green chilies. Spoon the yogurt mixture on and around the vadas, covering them completely as shown below.
Here is the last dahi vada, with the tarka-garnish of mustard seeds, red chillies, green chillies and curry leaves sizzled in hot oil. Note: add some sweet-sour tamarind chutney and a sprinkle of chaat masala for a delicious, mouth-puckering North Indian flavor instead of the tarka that is more South Indian.