Slice the chicken breast into bite-sized pieces and place them in a small glass mixing bowl.
Zest half of the lime into the bowl, then squeeze the juice of that half over the chicken.
Toss the chicken with the chili powder, cumin, sea salt, and black pepper until every piece is evenly coated.
Heat the olive oil in a large non-stick skillet over medium-high heat until shimmering.
Add the chicken to the skillet in a single layer and sear without moving for 3 minutes to develop a golden crust.
Flip the chicken and continue cooking for another 3-4 minutes until cooked through, then remove the chicken from the pan and set aside.
In the same skillet, add the sliced bell peppers, red onion, and jalapeño, sautéing for 4-5 minutes until the edges are slightly charred but the vegetables remain crisp-tender.
Prepare your serving bowl by adding the warm, fluffy cooked brown rice as the base.
Layer the spicy lime chicken and the charred vegetables over the rice.
Top the bowl with fresh avocado slices and a sprinkle of chopped cilantro.
Finish with a final squeeze of juice from the remaining lime half before serving.