In a small bowl, whisk together the chili powder, cumin, garlic powder, smoked paprika, salt, and black pepper to create the fajita spice seasoning.
In a medium bowl, toss the chicken strips with 1 tablespoon of olive oil and exactly half of the prepared spice seasoning.
Place a large heavy-bottomed skillet over medium-high heat; once hot, add the chicken and sear for 6 to 8 minutes until the internal temperature reaches 165°F (74°C).
Remove the cooked chicken from the skillet and set aside on a plate, covering loosely with foil to retain moisture.
Add the remaining 1 tablespoon of olive oil to the same skillet and sauté the bell peppers and red onion for 5 to 7 minutes until edges are charred but texture remains tender-crisp.
Stir the remaining spice seasoning and lime juice into the vegetable mixture, using a wooden spoon to scrape any browned bits from the bottom of the pan.
Divide the 2 cups of cooked brown rice evenly among four serving bowls.
Top each bowl with an equal portion of the sautéed fajita vegetables and the seared chicken strips.
Garnish each bowl with chopped fresh cilantro before serving.