Soak the dried tapioca cubes, tapioca strips, and peeled split mung beans in three separate bowls for 2 hours.

After soaking for 2 hours, cook the tapioca cubes and strips separately. Tapioca cubes cook faster and only need about 20–30 minutes, while tapioca strips require 30–45 minutes. Once cooked, rinse them with cold water to prevent sticking.

Black Grass Jelly: Mix 50g of black grass powder and 50g of sugar with 1 liter of water. Note that you should gradually pour the water into the black grass powder instead of adding the powder to the water, as it clumps easily. Then, bring the mixture to a boil, pour it into a mold, and let it cool. (You can find a detailed guide to making black grass jelly here.)

White Agar-Agar Jelly: Similarly, for agar-agar jelly, add 12g of agar-agar powder and 100g of sugar to a pot. Gradually add 1.5L water while stirring thoroughly to dissolve the powder. Once the agar-agar is fully dissolved, bring the mixture to a boil, pour it into a mold or container, and let it cool to set. Once the jellies have set, cut them into bite-sized cubes.

After soaking, boil 200g of peeled split mung beans. Once cooked, drain the water and mash or blend the beans into a smooth paste. Cook the mashed beans over low heat with 70–100g of sugar until the mixture thickens.

Wash the pandan leaves and tie them into a bundle.

Mix 400ml of coconut milk with 100ml of water and 100–150g of sugar. Cook the mixture over medium heat with pandan leaves, stirring frequently to avoid sticking to the bottom of the pot until it boils.

Once all the components are ready, layer them in a glass to serve. Start with mung bean paste at the bottom, followed by jelly, tapioca cubes, and tapioca strips. Finally, pour the coconut milk sauce on top. For a chilled version, add crushed ice to fill the glass. Now, enjoy your Vietnamese Rainbow Dessert!