Boil the magenta plant leaves to extract the colored water. Soak the sticky rice in this water overnight. Soak the mung beans until they expand, then drain. Cook the beans with just enough coconut milk to cover. Once the beans are cooked, mash them and mix in sugar and salt (about 1 1/3 cups sugar (280 g) per 2 1/4 lbs beans (1 kg), and 1 teaspoon salt).

Tear the banana leaves so you have two inner leaves and one outer leaf for each roll. Clean the leaves thoroughly and make sure they are soft.

Heat the coconut milk on the stove, add sugar and salt, and bring to a gentle boil. Add the soaked sticky rice and stir-fry until the coconut milk is absorbed and the rice grains are dry.

Once the rice is ready, lay out the banana leaves, divide the rice and bean filling evenly, and assemble as shown in the reference image. Tie the rolls securely and cook for 3 hours from the time the water starts boiling.