Heat the oil in a pan. Add the green chillies and crushed garlic and fry on medium heat for about 2 minutes or just till the raw smell of the garlic is gone. The garlic should remain white in color.
Add the potato cubes, half the turmeric powder and salt to taste.
Mix well whilst mashing half of the potatoes with the back of the ladle on medium heat for about 4 minutes.
Remove from heat and let cool.
Mix in the coriander leaves.
Shape the mixture into lemon-sized balls.
Mix together the gram flour, red chilli powder, remaining turmeric powder, bicarbonate of soda, asafoetida powder and salt to taste with water just enough to make a thick batter.
Dip each ball in the batter, then deep fry in hot oil in batches on medium flame until light golden brown in color.
Remove onto a paper towel to drain.