Season the chicken breast evenly with chipotle powder, sea salt, and black pepper.
Heat the olive oil in a skillet over medium-high heat and cook the chicken until golden and cooked through, approximately 6 to 7 minutes per side.
Transfer the chicken to a cutting board, let it rest for 3 minutes, then slice it into bite-sized strips.
In the same skillet, sauté the sliced bell peppers and onions until they are tender-crisp and show slight char marks.
Warm the black beans in a small saucepan over low heat or in the microwave until heated through.
In a small bowl, mash the avocado with half of the lime juice and a pinch of salt until creamy.
Assemble the bowl by layering the chopped romaine lettuce at the base, then topping with the sliced chicken, warm beans, and sautéed vegetables.
Finish the dish by adding the avocado mash, fresh cilantro, and a final drizzle of the remaining lime juice.