Place a potato on a cutting board between two chopsticks. Slice the potato into 1/4 inch slices, the chopsticks will prevent you from cutting all the way through.
Repeat the process with the remaining potatoes. Place each potato on the middle of each tinfoil sheet, sprinkle with salt and pepper over the top; fold the tinfoil to enclose.
Cook on the grill at 400 degrees until the potatoes are tender (approximately 25 minutes).
Remove potatoes from the grill and open carefully.