Soak whole mung beans for at least 12 hours or 1 day, changing the water 2-3 times during the soaking process. Once the mung beans are well-soaked, drain the excess water.
Preheat the air fryer to 180C for 10 minutes. Toss the cooked mung beans in 1 teaspoon of oil. Spread half of the mung beans on a crisping tray or parchment paper.