Cut the water chestnuts into small pieces. Divide them into separate bowls and soak each in water with your desired food coloring. Make sure the water covers the chestnuts so the color is even. Soak for 15–20 minutes, then drain well. Toss the colored chestnuts in the combined tapioca and arrowroot starches until coated. Use a strainer to shake off any excess starch. Repeat for each color. Boil the coated chestnuts in boiling water until they float, which means they’re cooked. Transfer immediately to ice water, then drain and soak in simple syrup.

To make the clear jelly, pour water into a pot and add agar powder. Stir to combine and let sit for 5–10 minutes. Bring to a simmer over medium heat, stirring until the agar dissolves. Once boiling, add sugar and stir until dissolved. Remove from heat and set aside.

To make the coconut jelly, follow the same method: add water to a pot, sprinkle in agar powder, and stir. Let sit for 5–10 minutes. Heat over medium, stirring until dissolved. When it boils, lower the heat, add sugar, and stir until dissolved. Gradually add coconut cream, mix well, then remove from heat.

To assemble, spoon a layer of coconut jelly into a glass or plastic cup and let it set. Add a layer of clear jelly, then add the ruby water chestnuts until the cup is half full. Top with jackfruit, then pour in more clear jelly to cover. Let it set, then add another layer of coconut jelly. Once set, add more ruby water chestnuts and jackfruit on top, then finish with a final layer of clear jelly. Chill before serving for best flavor.

If the clear or coconut jelly starts to set while you’re assembling, gently reheat over low heat before using for the next layer.