Slice the chicken breast into thin, even strips and place them in a small mixing bowl.
Toss the chicken with the chili powder, ground cumin, garlic powder, sea salt, and black pepper until well coated.
Heat the avocado oil in a large non-stick skillet over medium-high heat until shimmering.
Add the seasoned chicken strips to the skillet and sauté until golden brown and cooked through, about 5 to 7 minutes.
Remove the chicken from the skillet and set aside on a plate.
In the same skillet, add the sliced red and green bell peppers along with the red onion.
Sauté the vegetables for 4 to 5 minutes until they are tender-crisp and have developed a slight char.
Return the cooked chicken to the skillet, drizzle with fresh lime juice, and toss to combine all flavors.
Place the warm brown rice in the base of a serving bowl.
Top the rice with the chicken and pepper mixture, then finish with sliced avocado and a sprinkle of fresh cilantro.