The sesame seeds need to be dry to grind them up. You can soak them for 8 hours, then dehydrate them for 6 hours until dry. If you don't have a dehydrator, skip the soaking process and go straight into grinding them.
You can make it into lumps of coal for a fun Christmas treat. Form them into coal shapes using a spatula. Roll a lumpy ball first, then slide a rubber spatula over it to make flat areas.

Keeps for 2 weeks in the refrigerator.