1. Preheat a gas or charcoal grill with a medium-high heat.
2. Peel sweet potatoes and cut into 1/2-inch thick wedges. Toss the potatoes with oil, 1 teaspoon salt and 1/2 teaspoon pepper. Grill the potatoes until tender and grill marks appear, about 4 to 5 minutes per side. Sprinkle with cilantro.