Place the mung beans in the blender along with the ginger, garlic, chillies and salt and blend until smooth, using just enough water to get a slightly-runnier-than-pancake-batter consistency. Add the flours and veggies and mix well. Set aside for 10 minutes and mix again.
Heat a cast-iron or nonstick skillet over medium-high heat until water sprinkled on the surface skitters off and dries up immediately.
Spray on a thin coating of the oil and then place 1/2 cup of the batter in the center using a ladle with a rounded bottom. Use the bottom of the ladle to spread the batter into as thin a round as possible. This doesn't have to be crepe-like, but if you ladle it on too thick the inside might not cook through.
When the top looks dry and the edges turn brown, flip over and cook until golden-brown.