basically, put the starch in a small saucepan and slowly stir the
coconut milk into it. Like really get that shit blended down so it has
no lumps. Then add the rest of the ingredients and turn the heat on
about... medium. Stir it for about ten minutes -- you'll know when it's
done, it'll suddenly start clumping around the sides of the pot, and
then if you blend those lumps back in, it'll turn into a pudding.
I'll warn you: as a pastry cream, that shit will FUCKING GEL. It will turn into something so solid you can cut it with a knife and eat it in slices, once it cools. To get it more pudding texture, cut back the starch a little, maybe 2-3T