Preheat your oven to 400°F and line a large baking sheet with parchment paper for easy cleanup.
Dice the potato and chicken breast into uniform half-inch cubes to ensure they cook evenly.
In a large bowl, toss the potato, chicken, olive oil, sea salt, black pepper, chili powder, and cumin until well coated.
Spread the mixture in a single layer on the prepared baking sheet and roast for 20 minutes.
Add the sliced bell peppers and diced red onion to the sheet, tossing gently with the other ingredients, and roast for another 10 minutes.
While the vegetables finish, rinse the black beans and warm them in a small saucepan over low heat.
Assemble the bowl by layering the roasted potato and chicken mixture with the warm black beans.
Top with a dollop of Greek yogurt, fresh avocado slices, and a sprinkle of cilantro before serving.