In a large bowl, toss chicken strips with 1 tablespoon olive oil, chili powder, cumin, garlic powder, salt, and pepper.
Heat a large skillet over medium-high heat and cook chicken until browned and cooked through, approximately 8-10 minutes, then remove from pan.
In the same skillet, add the remaining olive oil, bell peppers, and red onion, sautéing until tender-crisp and slightly charred for 5-7 minutes.
Assemble the bowls by dividing the cooked rice and black beans equally among four serving containers.
Distribute the cooked chicken and sautéed fajita vegetables over the rice and bean base.
Top each bowl with corn kernels, sliced avocado, and a dollop of sour cream.
Garnish with fresh cilantro and serve with lime wedges for seasoning.