1. Dissolve the tapioca starch in 2 tablespoons of water. Set aside.
2. Heat a pot over medium heat, add all the ingredients except the tapioca starch.
3. Stir constantly until integrated and cook for 3 minutes.
4. When the mixture starts to boil, add the tapioca starch, stir well and cook for 1 more minute.
5. Grease a mold with a little truffle oil.
6. Pour the preparation into the mold, let it cool at room temperature and then refrigerate for 2 hours.