Place the chestnuts in a bowl together with red food coloring; mix well until the chestnuts are well coated with the food coloring. Let it sit at room temperature for 15-20 minutes.
Meanwhile, combine coconut cream, a quarter cup of water, pandan leaf, and salt in a saucepan. Bring the mixture to a simmer for 5 minutes.
Remove the simmered coconut sauce and let it cool completely before transferring it to a food container to cool in the fridge.
Drain any excess liquid in the water chestnuts and sprinkle with tapioca starch. Toss the chestnuts until well coated with the tapioca starch.
Place the remaining water in a pot and bring to a full boil.
Strain the rubies until excess starch is removed. Place it in the boiling water and cook for 2-3 minutes until they float.
Scoop out the rubies and transfer them to an iced bath.
Let it cool down for 10 minutes.
To assemble, simply combine drained cooked red rubies, jackfruit slices, syrup, and coconut sauce.
Mix well until fully incorporated and refrigerate for about 20 minutes to 1 hour.
Serve chilled.