First cut the onions
For batter- slightly beat the eggs, add the flour, salt,sugar, other spices/flavours and mix, add the milk/yogurt/buttermilk to make a thick batter.
For dry coating over the onion covered batter- mix the bread crumbs and the baking soda together in a slightly large vessel
Dip the onion rings into the wet batter and remove the rings one to two at a time with a fork and into the dry coating mixture. Toss the rings in the mixture till fully coated and set aside on a plate with another fork. Try keeping the forks as dry as possible to avoid lumps in the dry mixture.(if any lumps form mix them into the wet better)
After all the onion rings are coatedand on a plate. Put them in the fridge/freezer for 10-15 mins(until cool but not frozen!)
Meanwhile start heating the oil in a deep frier/ any vessel used for frying. The oil should be very hot(turn on gas at full whack)
Remove the rings from the fridge. Slowly slide the rings one at a time into the hot oil. So nit over crowd the vessel. Reduce the gas if rings start browning too fast. With the help of tongs/large spoon flip the rings once golden on one side. Cook each batch on both sides evenly and then remove them and place them on tissue paper/kitchen towels to drain off excess oil.
Sprinkle with additional salt/seasoning if required and enjoy them while hot and crispy!