2 pounds sweet potatoes (about 3 large), scrubbed and dried
3 tablespoons vegetable or olive oil, plus more for the grill grates
For the spicy honey-lime dressing (optional):
2 tablespoons honey
1 1/2 teaspoons vegetable or olive oil
1 1/2 teaspoons sambal oelek
1 1/2 teaspoons freshly squeezed lime juice
Pinch kosher salt
2 tablespoons coarsely chopped fresh cilantro leaves
1. Grill the sweet potatoes: Heat an outdoor grill for medium, direct heat (about 350°F). While the grill is heating, cut the sweet potatoes crosswise on a slight diagonal into 1/2-inch-thick slices. Place in a large bowl, drizzle with the oil, season with salt, and toss to combine.
2. Oil the grill grates. Place the sweet potato slices in a single layer on the grill. Cover and cook until grill marks appear, about 5 minutes. Flip the sweet potatoes, cover, and cook until the sweet potatoes are tender, about 5 minutes more. Meanwhile, make the dressing if using.
3. Make the dressing: Place the honey, oil, sambal, lime juice, and salt in a large bowl and whisk to combine. When the sweet potatoes are ready, transfer to the bowl with the dressing and toss to combine. Transfer to a serving platter, top with the cilantro, and serve.