In a bowl, soak the tapioca in 2 cups of room temperature water overnight.
Drain Water and set aside.
In a double boiler, heat the milk just until no longer cold.
Continue heating until small bubbles appear at sides of the pan. Cover, turn heat to very low and cook for 1 hour. Make sure that the milk mixture does not simmer or boil
This is how my mixture looked at 30 minutes.
Add the sugar and give it a quick stir. Cover and continue cooking for about 15 minutes
Mix the cornstarch with water until dissolved.
Add it to the tapioca mixture and stir.
Cover and continue cooking until very thick - another 15 minutes.
Stir in the vanilla. Mix and cook for 1 min and switch off the flame/heat.
Add the chocolate chips
Fold it into the tapioca and give it a stir
until it is completely blended well into the mixture.