Wash and soak 1 cup of peas dal (yellow split peas) in water for 4-5 hours or overnight.
Drain the soaked peas dal and transfer it to a grinder. Add 1-2 green chilies, a 1-inch piece of ginger, and salt to taste. Grind the mixture into a smooth batter, adding water as needed to achieve a dosa batter consistency.
Finely chop 1 medium-sized onion, 1 small tomato, and a handful of fresh coriander leaves. Mix these into the batter.
Heat a non-stick tawa or dosa pan over medium heat. 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 bottom turns golden brown and crisp.
Flip the dosa and cook the other side for a minute or until it turns golden brown.
Fold the dosa and transfer it to a serving plate. Repeat the process with the remaining batter.
Serve the matar dal dosa hot with coconut chutney or tomato chutney.