For preparing onion bajji, first prepare a thick batter with basen, cumin powder, chilly powder, asafoetida powder, turmeric powder, 1/4 cup water(or as needed) and required salt.
Dip the onion slices in the batter and deep fry in hot boiling oil until golden and crisp.
Kerala Onion bajji, a tasty evening time snack is ready. Serve hot and enjoy.