Soak urad dal in water for a minimum of 2 hours or overnight for best results.

Drain the urad dal and grind it into a smooth, thick batter with minimal water.

Transfer the batter to a large bowl and whisk until it becomes aerated and fluffy.

In a separate bowl, whisk together curd, water, salt, red chilli powder, roasted cumin, and black salt until smooth.

Mix in chopped mint and coriander leaves. Adjust seasoning as needed.

Heat mustard oil in a small pan until it begins to smoke. Remove from heat, add asafoetida and cumin seeds, allowing them to sizzle. Add this tempering to the chaas/buttermilk mixture and stir well.

Heat oil in a deep frying pan over medium heat.

With damp hands, form small portions of the batter into balls, then flatten slightly.

Carefully slide them into the hot oil, frying until golden brown (avoid overcrowding by frying in batches).

Drain on paper towels and soak the fried vadas in lukewarm water for 20-30 minutes to soften.

Squeeze out the water gently and immerse them in the prepared spiced chaas/buttermilk.

Refrigerate the chaas dahi vadas before serving.

Enjoy!