Preheat barbecue to medium heat. Layer sheets of foil. Brush top of foil with 1 Tbsp. of the oil. Slice potatoes into 1/4 inch thick slices and arrange in an overlapping single layer on the foil. Place garlic slices between the potatoes. Drizzle potatoes with remaining olive oil and lemon juice. Sprinkle with herbs and season with salt and pepper. Fold the foil over the potatoes and seal the top. Place package on the barbecue, close the lid, and cook 20-25 minutes, or until potatoes are tender.