Peel and thinly slice 250 grams of onions. Set aside.
In a mixing bowl, add 100 grams of gram flour (besan), 1/2 teaspoon red chili powder, 1/4 teaspoon turmeric powder, 1/2 teaspoon carom seeds (ajwain), 1/2 teaspoon cumin seeds (jeera), a pinch of asafoetida (hing), salt to taste, and 2 tablespoons of chopped coriander leaves. Mix well.
Gradually add water to the dry mixture and whisk until you get a thick, smooth batter. The consistency should be such that it coats the onion slices well.
Add the sliced onions to the batter and mix well, ensuring that the onions are evenly coated with the batter.
Heat oil in a deep frying pan or kadai over medium heat. Once the oil is hot, carefully drop spoonfuls of the onion-batter mixture into the oil.
Fry the pakodas until they turn golden brown and crispy, turning them occasionally to ensure even cooking.
Use a slotted spoon to remove the pakodas from the oil and place them on a paper towel-lined plate to absorb excess oil.
Serve the pyaaz pakodas hot with green chutney or tomato ketchup.