Whisk besan with water gradually until smooth and lump-free. The batter should be thin and pourable, like crêpe batter.
Add green chili, ginger, coriander, cumin seeds, turmeric, red chili powder, and salt. Mix well.
Rest the batter for 5 minutes to help the flour hydrate fully.
Cook the chilla
Heat a non-stick pan or tawa on medium-high heat until very hot. A drop of water should sizzle and evaporate immediately.
Drizzle ½ tsp oil and spread it across the pan.
Pour ¼ cup batter into the center and spread thin in a circular motion with the back of the ladle to make a round about 6–7 inches wide.
Drizzle a few drops of oil around the edges. Cook on medium heat for 2–3 minutes until the edges lift and the surface looks set.
Flip carefully with a flat spatula. Cook the other side for 1–2 minutes until golden.
Remove and serve immediately with chutney or yogurt.
Notes
Batter consistency: aim for thin and pourable, slightly thinner than dosa batter. It should coat and run off a spoon easily.Hot pan is essential: starting on a cold pan causes chilla to stick and tear.Don't press down after flipping. Let it cook undisturbed for crispy results.Jain / no-onion-garlic version: skip the green chili; add a pinch of ajwain (carom seeds) instead.Store cooked chilla in an airtight container in the fridge for up to 2 days. Reheat on a dry pan to restore crispiness.