Soak Mung beans for 12 hours. Drain the water mung has been soaking in and wash gently once or twice with fresh water taking care NOT to remove the mung hull. Grind them in food processor while adding some water to make a thick batter. Leave this batter for about 2-3 hours at room temperature and it is ready for making pancakes. Batter can me made in advance and kept in fridge to make pancakes whenever needed for breakfast or meals. For a variation in taste a fermented batter could be used. For fermentation, leave the batter at room temperature for 8-10 hours. For a faster fermentation preheat the oven for one minute and turn it off (Selecting oven temperature is not important because by pre-heating only for one minute the temperature will be much less than the lowest temperature your oven goes to). The oven should be very slightly warm so that you can touch the oven racks easily. Make sure twice that the oven is off. Leave the batter in the oven and the fermentation is much faster than room temperature. Do NOT use any yeast to ferment.
Take out from the fridge the amount of batter needed for pancakes. Keep the rest of it back in the fridge for later. Veggies and salt added to all of the batter will result in a watery batter if kept in fridge all premixed. This is due to juice extracted from the veggies by the salt in the mixture.
Finely chop the bell pepper, onion, cilantro and hot pepper. Add these veggies and salt to the mung batter. Mix them together with a spoon. On a preheated cast iron pan (a well seasoned cast iron pan becomes non-stick) add some oil. Add a large spoonful of the mixture to the pan and spread to make about 1/4 inch thick pancake. Cook on medium heat. Cover the pan with a lid so that the steam will set the the pancake's top surface and it will not splatter during turning. After the top surface has set cook for another 2-3 minutes. Flip the pancake and cook some more covered or uncovered. Smaller pancakes will be easier to flip.
Serve this pancake with yogurt or any chutney or salsa.