Simple and low in fat.
Place potatoes in medium saucepan. Cover with water; bring to boil. Boil potatoes until just tender when pierced with small sharp knife. Cool. Peel potatoes. Cut lengthwise into 1/2-inch-thick slices.
Prepare barbecue (medium-high heat) or preheat broiler. Brush potatoes with oil. Sprinkle with rosemary, salt and pepper. Grill potatoes until beginning to brown, about 4 minutes per side.