Whisk yogurt in a medium-sized bowl until smooth and creamy.
Add the chickpea flour to the bowl and whisk well to make a smooth lump-free mixture.
Add water to the bowl and mix well until combined.
Pro Tip: The No-Lump Rule: The besan mixture must be lump-free. Always sift besan before mixing. If you see lumps, pass the mixture through a fine-mesh strainer.
Heat oil in a pan over medium-high heat.
Once the oil is hot, add fenugreek seeds, mustard seeds, cumin seeds, curry leaves, and asafetida, and let them crackle for 2-3 seconds.
Now add the chickpea flour mixture to the pan and mix well.
Add the turmeric powder, red chili powder, and salt to the pan and bring the mixture to a boil.
Once the mixture comes to a boil, reduce the heat to low and cook the kadhi for 20-25 minutes until it thickens. Stir frequently.
Don’t Rush the Cook: Undercooking the besan gives kadhi a raw, floury taste that no tadka can fix. Taste after 20 minutes, it should taste clean and tangy, not gluey.
Keep the flame low after the initial boil. Aggressive heat breaks the emulsion and splits the kadhi.
Add boondi and mix gently. Simmer for 3–4 minutes so the boondi absorbs the gravy and softens. Switch off the heat.
Temper The Boondi Kadhi
Heat ghee in a small pan over medium heat.
Once the ghee is hot, add the broken, dry red chilies and fry for 2 seconds.
Remove the pan from the heat and add the red chili powder.
Now, immediately pour the tempering over the kadhi. Be quick after adding the chili powder to the hot oil; otherwise, it may burn.
If your kadhi is not tangy enough, add some lime juice.