In a bowl, mix together besan, salt, red chilli powder and cumin seeds.
Add water little by little until thick batter is formed. This batter should not either be too thick or too thin.
Heat oil for deep frying on medium flame.
Add the onions to the batter & mix and drop one Tbsp of batter in the oil for 3 times (or more depending on space available for frying). The oil should not be over crowded with the batter.
Fry the fritters until they are brown on both the sides. Remove them onto a kitchen towel so that the excess oil is absorbed.
Use up all the batter in turns.