Instructions

1. In a large saucepan, add whole sweet potatoes and cover with cold salted water by 1 inch. Bring to a simmer, covered, and cook until just tender, about 15 to 30 minutes, depending on size of potatoes. Test with a knife.
2. Place potatoes in a a colander and run under cold water to cool. With a sharp knife peel potatoes and cut crosswise into 1/2-inch-thick slices.
3. In a small bowl whisk together oil, salt, and cumin and brush some onto both sides of potato slices, reserving remaining cumin oil.
4. Preheat your grill. Grill potato slices on an oiled rack set 5 to 6 inches over glowing coals until golden brown, about 1 minute on each side, and transfer to a platter. Sprinkle green onion over grilled potatoes. Whisk lime juice into remaining cumin oil with salt and pepper to taste and drizzle over potatoes. Serve potato salad with additional lime wedges and chopped cilantro if desired.
5. Updated: I just wanted to note to keep an eye on your potatoes as they are boiling, you want them firm and not too soft. But you want to parboil them enough to take the bite out of them so they aren’t completely raw on the grill.
6. Also, according to one of the reviews on epicurious, the potatoes can be boiled and sliced ahead of time and grilled later.