Rinse the Toor dal and Channa dal thoroughly and soak them in water for about 3-4 hours. Drain the daal completely using a sieve and set it aside.

In a grinder, combine dry red chillies, green chillies, fennel seeds, coconut, garlic cloves, (if using), ginger, and curry leaves. Coarsely grind the mixture without adding water.

Reserve a small portion of the soaked dal and combine the rest with the ground mixture in the grinder. Pulse them together without adding water until the mixture can be shaped into round balls. If needed, add 1-2 tbsp of water to help bind the dough.

Transfer the mixture to a mixing bowl and add shallots, salt, hing and the reserved dal. Mix well, adjusting the taste by adding more salt if necessary. Add 1 tbsp of hot oil to the mixture.

Apply a little oil to your palm, then take small portions of the mixture, shape them into lemon-sized balls, and flatten them on your palm. Set aside.

Heat oil in a frying pan over medium-high heat. Test the oil temperature by dropping a small portion of the dough; it should rise without browning quickly.

Carefully slide the shaped vadai into the hot oil, allowing them to cook undisturbed for a few minutes until they firm up (2-3 minutes). Flip them to the other side once they start releasing from the bottom of the frying pan.

Fry the vada in batches on both sides until they turn evenly golden and crisp. Transfer them to a paper-lined plate to absorb excess oil.

Repeat the process for the remaining vadai.

Serve hot with coconut chutney or green chutney.