1 teaspoon ground cumin
1 teaspoon smoked paprika
1/2 teaspoon cayenne
1 1/2 pounds sweet potatoes, peeled, halved or quartered lengthwise, and sliced crosswise 1/3 inch thick
2 tablespoons butter, cut into pieces
1 tablespoon brown sugar
2 teaspoons lemon juice
In a 12-inch skillet over medium-high, whisk together 1 1/2 cups water, the cumin, paprika, cayenne and about 1 teaspoon of salt. Add the potatoes, then cover the skillet and bring the liquid to a boil. When it boils, reduce the heat to a simmer and cook the potatoes, covered, for 3 to 5 minutes. Remove the lid and prick the potatoes with a paring knife. If they are almost tender, remove the lid and increase the temperature so that the liquid boils. If they are not almost tender, cover the potatoes and cook, covered, for another minute or so, then remove the lid.
Boil the liquid until it only comes up the side of the skillet about 1/4 inch. Add the butter, brown sugar and lemon juice, then simmer, stirring gently, until the liquid is reduced to a glaze. Season with salt and serve immediately.