Firstly add rice flour, water, salt, and curd to a wide vessel; mix well till you get Lump free smooth batter
Add oil to a wide heavy-bottomed pan and pour rice flour slurry
Turn on the stove in low- medium flame and keep mixing for a lump-free smooth dough
Thickens well and dough comes together
Without touching the pan it turns to a whole mass
Check if the dough is at the right consistency, Nonstick when touched with wet hands
Vadai dough is ready; turn off the stove
Transfer to a plate and cover with a damp cloth
Warm enough to roll? Grease with little oil and mix well; If the dough has any lumps, break it
Add onion, ginger, asafoetida, curry leaves, green chilli, and dried red chilli flakes; mix well
Grease your hands with little oil and pinch a portion of the dough
Roll and flatten. Make a hole in the center
Heat oil and fry vadai in batches
Avoid flipping immediately. Give time to fry
Flip and fry both sides golden brown
Drain oil in the oil filter and serve hot vadai