Preheat your oven to 400°F (200°C) and line a baking sheet with parchment paper.
Slice the red bell pepper and yellow onion into thin strips. Toss them on the baking sheet with 0.5 tablespoon of olive oil and a pinch of sea salt.
Roast the vegetables for 18-20 minutes until they are tender and show dark, charred edges.
While the vegetables roast, slice the chicken breast into thin strips and place in a bowl. Toss with the remaining 0.5 tablespoon of olive oil, chili powder, cumin, sea salt, and black pepper.
Heat a non-stick skillet over medium-high heat. Add the chicken and sauté for 6-8 minutes, stirring occasionally, until cooked through and golden brown.
Warm the pre-cooked brown rice and place it at the base of a serving bowl.
Layer the roasted peppers, onions, and sautéed chicken over the rice.
Garnish with sliced avocado, fresh cilantro, and a generous squeeze of lime juice before serving.