Soak the Mung Beans: Rinse the split mung beans until the water runs clear.1 Add water to cover the mung beans and soak for approximately 4 hours.
Steam the Mung Beans: Pour the water off of the soaked mung beans, then transfer the beans to a damp cheesecloth. Place the cheesecloth-wrapped beans in the top of a steamer pot. Add water to the bottom of the steamer, close the lid, and bring to a boil. Allow the beans to steam for 15 minutes, then remove and place the beans on a paper towel to absorb any extra moisture.2
Fry the Mung Beans: Add oil to a pot and heat to medium high. Once the oil is hot, add the steamed mung beans and allow to fry until they are golden brown and crispy. In my experience, this takes about 5 minutes. Remove the mung beans from the oil and drain on a paper towel.3
Sprinkle with Salt: Sprinkle the crispy mung beans with salt. Enjoy as a crunchy snack or use as a topping for various Thai desserts.
Notes
Peeled split mung beans often have yellow dye added to make them even brighter yellow. Your initial rinses may be quite yellow, but the water will turn clear with enough rinsing.
You want to rehydrate the mung beans without making them soggy. Once they've steamed for 15 minutes, take one out to check it. It should still be firm, yet able to be smashed between your fingers. If it can't be crushed, steam it for 5 more minutes.
When the mung beans are initially added to the oil, the oil will bubble a lot. When the mung beans are done, there will be significantly fewer bubbles.