In a mixing bowl, wash poha, rice, and urad dal. Then add buttermilk and mix well. Soak the mixture for 3 hours.
After soaking, transfer the mixture to a blender jar without adding any water. Grind it into a smooth and medium-thick batter.
Pour the batter back into the mixing bowl.
Add salt, sugar, and baking soda to the batter. Mix well and whisk for 2 minutes.
Heat a tawa (griddle) and sprinkle water on it. Wipe off the water with a cloth to cool down the temperature of the tawa.
Take 2 small ladlefuls of batter and spread it evenly on the tawa.
Apply oil or butter on the dosa and roast it on medium flame until crispy.
Serve the crispy dosa with spicy red chutney.