Cooked moong (or mung) beans are the protein part of a Gujarati thali, generally eaten along with rotli, Gujarati bread. The best part of this dish is that these moong beans can be also be had on their own as a snack or a meal. Add diced red onions, tomatoes, garnish with cilantro, and you're done. —Annada Rathi
Soak moong beans in 2 cups water for at least 12 hours. You may find some beans have not soaked at all. If that's the case, change the water and soak for another 4 to 5 hours. This is important as you don't want dry, un-soaked beans to be a part of this dish. Drain the beans and discard the water.
Heat oil in a pan on medium heat. After 3 to 4 minutes, add mustard and cumin seeds.
Once the seeds stop popping, add garlic, chile pepper, red chile powder, and turmeric. Stir once and add beans right away. Otherwise the red chile powder and turmeric may burn.
Add 1/4 cup water, salt, sugar and lime juice. Bring to a simmer, cover, and cook for 10 minutes. If the beans are too al dente for your taste, cook longer.
Turn the heat off and serve warm. Serve with Gujarati bread, rotli. To eat it as a snack, add 1/4 cup diced red onions, 1/8 cup diced red tomatoes to 1 cup of cooked moong beans. Garnish with cilantro.