Cooking fajitas on a baking sheet means they're ready fast -- with less oil and less mess. Zesty chicken, vegetables and beans are delicious served over rice for a gluten-free meal, but you could also stuff the fajita filling into tortillas.
Cook the rice according to the package directions. Preheat the broiler to high with the rack in the highest position. Line a rimmed baking sheet with foil.
Put the chili powder, cumin, 1 1/2 teaspoons salt, 1/2 teaspoon pepper and oil in a large bowl and whisk to combine.
Add the chicken, peppers and onions to the bowl and toss to coat well. Scatter the chicken and vegetables in an even layer on the prepared baking sheet and broil until the vegetables are starting to char and soften and the chicken is cooked through, about 10 minutes.
Meanwhile, combine the black beans and 2 tablespoons lime juice in a small bowl. Once the chicken and vegetables are out of the oven, add the beans to the baking sheet and toss to combine. (The heat from the fajitas will warm the beans.)
Meanwhile, make the sour cream drizzle: Put the remaining 2 tablespoons lime juice, sour cream and cilantro in the bowl of a mini food processor and pulse until mostly smooth and green. Season to taste with salt and pepper.
Divide the rice between 4 bowls and top with the fajita mixture. Drizzle with the sour cream mixture before serving.