Slice the peppers in half vertically (from the top of the stem to the bottom of the pepper). Remove the seeds. For extra color, use one pepper of each color: green, red, yellow and orange. If you prefer your peppers soft, parboil them for 5 minutes.
Preheat the oven to 450 degrees F.
Combine the chicken, chili powder, cumin, 1/2 teaspoon salt and several grinds of pepper in a large bowl and toss to coat.
Heat 1 tablespoon of the oil in a large cast-iron skillet over medium-high heat until it just begins to smoke. Add the chicken and cook, undisturbed, until it just starts to brown in spots, about 2 minutes. Add the onion and cook, stirring often, until the onions are tender, about 3 minutes more.
Transfer the chicken and onion mixture to a large bowl and rinse and dry the skillet. Add the rice, 1/2 cup of the cheese, half the lime juice, 3/4 teaspoon salt and few grinds of pepper to the chicken and toss to combine. Divide the filling among the peppers.
Add the remaining tablespoon of oil to the skillet, arrange the peppers on top and turn to high heat. When the oil starts to sizzle, about 2 minutes, transfer to the oven and bake until the filling is hot and the peppers are softened, about 20 minutes. Sprinkle the remaining 1/2 cup cheese over the peppers and bake until melted, about 3 minutes more.
Get all the zesty flavors of sizzling fajitas in a healthy stuffed pepper that’s easy enough for a weeknight meal.