Heat a griddle and pour a thick ladle of dosa batter without spreading too thin.
Sprinkle chopped onion, tomato, green chili, coriander leaves, and salt over wet batter, pressing gently.
Drizzle oil around edges, cover, and cook on medium flame for 3 minutes.
Flip and cook for 2 minutes until toppings turn light brown and cooked.
Serve hot with coconut chutney.