In a high pressure cooker, add clean water to slightly cover the mung beans and cook with a bean procedure until the beans are soft and easy to smash. Then smash them with a spatula until a smooth and fine mixture. Transfer it to a non-stick pan.
How to keep: wrap with plastic wrap and store in fridge up for 1 week.
You can also use this directly as a mung bean filling for mooncakes.
For vegan readers, you can skip butter and replace it with vegetable cooking oil.