Prepare a charcoal or gas grill to medium heat. Keep one side open for indirect cooking.
Toss all ingredients together in a large bowl. Tear two lengths of foil, about 16-inches long each. Divide potato mixture between the two sheets of foil and fold the sides up over the potatoes to create a secure package so no steam can escape.
Grill potatoes over medium heat for about 10 minutes. Flip and grill another 10-15 minutes, or until potatoes are tender when pierced with a fork. Transfer to the indirect heating side if the garlic is starting to burn before the potatoes are tender. Taste and add more salt and pepper if needed. Serve hot with pork chops, steaks, or burgers.