Add moong dal to a medium bowl. Rinse the moong dal. Add 3 cups water and soak for at least 3 hours or overnight.
Drain the water. Transfer dal to a blender. Add about ⅔ cup water. Blend to make a smooth batter.
Transfer the batter to a bowl. Add green chili, ginger, onion, cilantro, salt, turmeric and red chili powder. Mix well, and add 1-2 tablespoons more water if needed. Make sure the batter is not too thick or too runny, it should have a pouring consistency.
Heat an iron skillet on medium heat. Using the same ladle, spread the batter on the tawa in a circular motion to make a round chilla. Now turn the heat to medium-high.Once the skillet is hot, turn the heat to low, take a ladle full of the batter, and pour it at the center of the pan.
Drizzle some oil at the edges of the chilla and at the center on the top. Total of about ¾ to 1 teaspoon. Cook the chilla on one side for a couple of minutes, then flip it using a spatula. You should see some golden spots on the top of the chilla after it was flipped.
Now press with the spatula and cook the other side for 1-2 minutes.
When the chilla is well cooked on both sides, remove to a plate. Same way make all the chilla's. Wipe the pan with a paper towel between each chilla.