Roast the cumin seeds and coriander seeds in a dry pan until fragrant, then crush them coarsely.

Thinly slice the onion and potato, then wash and roughly chop the spinach.

Combine chickpea flour, crushed cumin seeds, crushed coriander seeds, dried fenugreek leaves, red chili flakes, chaat masala, turmeric, carom seeds, baking soda, and salt in a mixing bowl.

Gradually whisk in up to 120 ml (1/2 cup) water to make a thick, light-coating batter; use as little water as possible.

Heat the neutral frying oil in a deep pan over medium-high heat until a small drop of batter sizzles immediately.

Dip the onion slices, spinach, and potato slices into the batter, coating each piece lightly and evenly.

Fry the coated vegetables in small batches until golden brown and crisp, about 3 to 4 minutes per batch.

Lift the pakoras out with a slotted spoon and drain them briefly on paper towel before serving hot.