Preheat your oven to 400°F (200°C) and line a baking sheet with parchment paper.
Slice the bell pepper, red onion, and zucchini into uniform strips.
Toss the vegetables on the baking sheet with half of the olive oil, a pinch of sea salt, and black pepper.
Roast the vegetables for 15-20 minutes until they are tender and show slight charred edges.
While vegetables roast, season the chicken breast evenly with cumin, chili powder, sea salt, and black pepper.
Heat the remaining olive oil in a skillet over medium-high heat and cook the chicken for 6-7 minutes per side until the internal temperature reaches 165°F.
Remove the chicken from the pan, let it rest for 5 minutes, then slice into thin strips.
Rinse and drain the black beans thoroughly.
Assemble the bowl by placing the chopped romaine lettuce at the base.
Arrange the roasted vegetables, black beans, sliced chicken, and avocado on top of the greens.
Finish the bowl with a fresh squeeze of lime juice for brightness.