4 large sweet potatoes
1/2 cup extra-virgin olive oil, divided
Salt and freshly ground black pepper
1/4 cup red-wine vinegar
1 medium red bell pepper, cored, seeded, and quartered
2 teaspoons ground cumin
1 tablespoon grated orange zest
1/2 cup sliced scallion
1/2 cup minced fresh mint leaves
1 or 2 fresh minced chiles (jalapeño, Thai, serrano, or habanero), or to taste

1/4 cup raisins (optional)

4 large sweet potatoes 1/2 cup extra-virgin olive oil, divided 1/4 cup red-wine vinegar 1 medium red bell pepper, cored, seeded, and quartered 2 teaspoons ground cumin 1 tablespoon grated orange zest 1/2 cup sliced scallion 1/2 cup minced fresh mint leaves 1 or 2 fresh minced chiles (jalapeño, Thai, serrano, or habanero), or to taste 1/4 cup raisins (optional)

Preheat the oven to 400˚F. Peel the sweet potatoes and cut them into bite-size pieces. Put them on a baking sheet, drizzle with two tablespoons of the oil, and toss to coat. Sprinkle with salt and pepper, and roast, turning occasionally, until crisp and brown outside and just tender inside, about 30 minutes. Remove and keep on the pan until ready to dress.

Make the dressing while the potatoes cook. Put the remaining six tablespoons of oil in a blender, along with the vinegar, bell pepper, cumin, and zest if you're using it. Sprinkle with a little salt and pepper. Purée until smooth.

Toss the warm potatoes with the scallion, mint, chiles, and raisins if you're using them. Add 1/2 cup of the dressing, and toss to coat, adding more if necessary. Taste and adjust the seasoning. Serve immediately or at room temperature.