Soak all the dried ingredients in hot water until they expand, then discard the soaking water to remove any dust. Simmer the lotus seeds until tender. Soak the butterfly pea flowers in 3 cups hot water (about 700 ml) until the color is released, then strain out the flowers. Squeeze in the juice of half a lemon to turn the water a pinkish-purple color.

Cook the agar agar with 1 can of coconut milk. Bring to a boil, then add the agar agar powder and 1/3 cup granulated sugar, stirring until dissolved. Pour the mixture into a mold and let it set, then cut into small cubes. Soak the seaweed in hot water until it expands, then rinse well. Once the dried fruits and lotus seeds are soft, add them to a pot with the butterfly pea flower water. Bring to a boil, then add the palm sugar and adjust sweetness to taste. Turn off the heat and let cool slightly before adding the coconut jelly cubes.

Finally, add the seaweed. Serve the sweet soup chilled.