hat tip to Jeri Tindal
3 1/2 lb sweet potatoes, peeled and cut into 1/2-inch cubes (10 cups)
1/2 stick (1/4 cup) unsalted butter, melted
3/4 teaspoon salt
1/2 teaspoon black pepper
1/4 cup water
2 tablespoons sugar
1 tablespoon fresh lime juice
1/2 teaspoon finely grated fresh lime zest
2 tablespoons finely chopped fresh chives
Put oven racks in upper and lower thirds of oven and preheat oven to 450°F.
Toss potatoes with butter, salt, and pepper in a bowl until coated well, then spread in 1 layer in 2 shallow baking pans (15 by 10 by 1 inch) and roast, uncovered, switching position of pans halfway through roasting, until potatoes are tender and undersides are browned, 15 to 20 minutes total.
While potatoes roast, bring water, sugar, and lime juice to a boil in a very small saucepan, stirring until sugar is dissolved, then simmer until reduced to about 3 tablespoons, 3 to 4 minutes. Toss potatoes with syrup and zest in a large bowl, then sprinkle with chives.