Prep vegetables: Thinly slice the onion, grate the potato and carrot, chop cauliflower into small florets, and roughly chop spinach (if using). Lightly squeeze any excess moisture from grated potato or watery vegetables.
Mix dry ingredients: In a large bowl, whisk together chickpea flour, rice/cornflour, baking powder, ground cumin, coriander, garam masala, chili powder, turmeric, and salt.
Combine veg + seasoning: Add all prepared vegetables, green chilies, and chopped cilantro to the dry mix. Toss so the vegetables are evenly coated. Add lemon juice if using.
Form the batter: Sprinkle 2–3 tablespoons of water and toss. The mixture should be thick and cling together when pressed — not runny. Add water in small increments until you can shape spoonfuls that hold their shape.
Heat oil: In a heavy-bottomed pot or deep fryer, pour oil to a depth of ~4–5 cm. Heat to 170–180°C (340–355°F). If you don’t have a thermometer, test by dropping a small pinch of batter — it should sizzle and float up, browning in ~3–4 minutes.
Fry in batches: Using a tablespoon, drop heaped spoonfuls of batter into hot oil (don’t overcrowd). Fry 3–5 minutes per batch, turning occasionally, until deep golden and crisp. Maintain oil temperature between 165–180°C.
Drain & season: Remove pakoras with a slotted spoon and drain on a wire rack (preferred) or paper towels. Sprinkle a pinch of salt immediately while hot.
Serve: Serve hot with mint-coriander chutney, tamarind chutney, or a cooling raita. For parties, serve on a platter with lemon wedges and extra chutney bowls.