Lime Cilantro Sweet Potatoes

    2 lb. sweet potatoes, peeled and cut into 3/4-inch pieces
    3 tablespoons extra-virgin olive oil
    3/4 teaspoon salt
    1/4 teaspoon cayenne
    1/2 teaspoon finely grated fresh lime zest
    1 tablespoon fresh lime juice
    1/4 cup chopped fresh cilantro

Put oven rack in lower third of oven and preheat oven to 425F. Toss
sweet potatoes with 2 tablespoons oil and 1/4 teaspoon salt in a
shallow baking pan. Arrange potatoes in 1 layer and roast, stirring
halfway through roasting, until tender, about 25 minutes total. Stir
together cayenne, zest, and remaining 1/2 teaspoon salt in a small
bowl. Whisk together lime juice and remaining tablespoon oil in a
medium bowl, then add potatoes. Sprinkle with cayenne mixture and
cilantro, stirring gently to combine.