Take 1 cup of oats and grind them into a fine powder using a mixer grinder.
In a large mixing bowl, combine the ground oats, 1/2 cup rice flour, 1/4 cup finely chopped onions, 1/4 cup grated carrot, 1/4 cup chopped coriander leaves, 1 finely chopped green chili, 1/2 teaspoon cumin seeds, and salt to taste.
Gradually add water to the mixture and mix well to form a smooth, pouring consistency batter. Let the batter rest for 15-20 minutes.
Heat a non-stick tawa or dosa pan on medium flame. Once hot, pour a ladleful of batter onto the tawa and spread it evenly in a circular motion to form a thin dosa.
Drizzle 1 teaspoon of oil around the edges of the dosa and cook until the dosa turns golden brown and crisp.
Flip the dosa and cook the other side for a minute.
Fold the dosa and transfer it to a serving plate. Repeat the process with the remaining batter.
Serve the oats dosa hot with coconut chutney or sambar.