Preheat your grill to high.
You will need heavy duty aluminum foil or double thickness of regular foil. You need enough to encase a sliced up potato.
To make one potato packet:
1 medium sized potato- peeled or not and sliced thinly
1 Tablespoon unsalted butter
Arrange your sliced potato on a rectangle of aluminum foil.
Add the butter and season with the garlic powder, salt, and pepper.
Bring up the edges of foil together and seal tightly.
Lay the packet on the grill rack and cook 20-30 minutes, turning halfway through the cooking time.
The potatoes are done when the packet has puffed up.
It is also great to add other fresh vegetables to your packet. Ideas are onions or green peppers.
Fresh herbs are great to add, if you have any on hand.
Parmesan cheese is also good.