Step 1

Position rack in the upper third of oven. Preheat to 400 degrees F.

Step 2

Using a spiral vegetable slicer or a julienne or regular vegetable peeler, cut sweet potatoes lengthwise into long, thin strands.

Step 3

Whisk 2 tablespoons oil, chili powder, cumin, garlic powder and 1/2 teaspoon salt in a large bowl. Add chicken and onions; toss to coat well. Spread on a large rimmed baking sheet. Roast on the top rack for 12 minutes.

Step 4

Meanwhile, place the sweet potato strands in a food processor and pulse until about the size of rice grains. Heat the remaining 1 tablespoon oil in a large nonstick skillet over medium heat. Add the sweet potato "rice," water, pepper and the remaining 1/4 teaspoon salt; cook, stirring, until tender and the water has evaporated, 4 to 6 minutes.

Step 5

After the chicken has roasted for 12 minutes, turn broiler on high. Broil until the chicken is cooked through and the onions are browned in spots, about 5 minutes more.

Step 6

To serve, place about 3/4 cup sweet potato "rice" in each of 4 shallow bowls. Top with equal amounts of the chicken-onion mixture, salsa, cheese and cilantro. Serve with lime wedges.