One thing that we talk a lot about on Earth Eats is blanching and shocking. This is the process of flash-cooking vegetables in boiling salted water for 2-3 minutes and then submerging them in ice water to seal in the nutrients and maintain the green color.
If you were to cook them in less than boiling water, they would turn a khaki army green, and they would also leech out a lot more of their minerals.
After blanching and shocking the veggies, they are ready to be added to a pan for cooking or they can be stored in the refrigerator for a couple days. The long beans we blanched and shocked are tasty in cold salads and even when you're searching the fridge for a midnight snack.
More: Here's another way to prepare long beans. You won't be able to keep your hands off this snack-worthy dish.