Inspired in Clara Davis Recipe https://clara-davis.com/sets/biomaterials-bioplastics/
To prepare the ingredients, first, crush the eggshell until it becomes a powder, and then measure all the amounts of all the ingredients you need.
Secondly, put all the ingredients in the cooking pot and mix with a spoon.
Then, start heating the mix while you keep stirring to avoid lumps. The mixture would be ready when reachs the boiling point.
After that, remove from heat and pour the mix in the mould to let it dry there. Approximately, the mixture will be dry in XX* hours at an X* environment, but in other conditions can take less or longer.