Preheat the oven to 200°C or 400°F. Lightly grease or line a baking tray.
In a mixing bowl, combine the gram flour, onion, spinach, green chilies, red chili powder, coriander powder, garam masala and salt.
Add water gradually and mix until a thick, spreadable batter forms.
Arrange the naan on the prepared baking tray.
Spread the besan mixture evenly over each naan, leaving a small border around the edges.
Garnish with additional green chili slices, if desired.
Bake for 8–12 minutes or until the topping is completely cooked and the naan is lightly crisp around the edges.
Remove from the oven and immediately brush with melted desi ghee.
Cut into wedges and serve hot with raita, chutney or pickle.