In a bowl, combine semolina, rice flour , all purpose flour, cumin seeds and salt.
Mix the ingredients with water and make sure there are no lumps. The batter consistency should be relative thin, almost watery or pouring.
Add coriander leaves, ginger and green chilli. Mix well.
Take a non stick pan and pour the batter from edges toward the middle, add ½ tsp oil over the dosa.
On medium flame, fry or roast the dosa till it turns crispy golden and the edges start to raise.
No need to roast on the other side, fold the dosa right in the middle and serve hot with coconut chutney and sambar.