In a bowl, combine the chipotle powder, cumin, garlic powder, onion powder, salt, and pepper. Rub this mixture evenly over the chicken breasts. Allow to marinate for at least 30 minutes (or up to 2 hours for more flavor) in the refrigerator.
Heat the olive oil in a skillet over medium heat. Add the marinated chicken breasts and cook for 6-7 minutes on each side, or until the internal temperature reaches 165°F (75°C). Remove from heat and let rest for 5 minutes before slicing.
In individual bowls, start with a layer of cooked brown rice at the bottom.
Evenly distribute the black beans and corn over the rice. Top with the sliced chicken, diced avocado, cherry tomatoes, and diced red onion.
Squeeze fresh lime juice over each bowl and garnish with chopped cilantro. Optionally, add a dollop of sour cream or Greek yogurt on the side for extra creaminess.
Serve immediately while warm, allowing each person to mix and match their ingredients for a personalized bowl.
Notes
Marinate the chicken for longer for enhanced flavor.