I use this a lot to jazz up simple rice bowls or anything that could use a little nori boost. You need a sharp knife for this.
What you will need
1 piece of nori
A very sharp knife
How to cook
Wave the piece of nori over one of the burners on your stove. Keep it moving so it toasts evenly. You will notice as it becomes dryer and firmer to almost crispy.
Now fold your nori, and, with a very sharp knife, slice finely.