1Heat gas or charcoal grill. Cut 2 (30x18-inch) sheets of heavy-duty foil. Divide potato slices evenly onto foil sheets. Sprinkle with salt.
2In small bowl, mix remaining ingredients; sprinkle over potatoes. Bring up 2 sides of foil so edges meet. Seal edges, making tight 1/2-inch fold; fold again, allowing space for heat circulation and expansion. Fold other sides to seal.
3Place packets, seam side up, on grill. Cover grill; cook over medium heat 18 to 23 minutes, rotating packets once, until potatoes are tender.
4To serve, place packets on plates. Cut large X across top of each packet; carefully fold back foil to allow steam to escape.