Preheat your oven to 400°F and line a large rimmed sheet pan with parchment paper for easy cleanup.
Cut the chicken breast into 1-inch bite-sized cubes and place them in a large mixing bowl.
Chop the broccoli into bite-sized florets and slice the red bell pepper into 1-inch wide strips, adding them to the bowl with the chicken.
In a small jar or bowl, whisk together the extra virgin olive oil, lemon juice, lemon zest, dried oregano, garlic powder, sea salt, and black pepper.
Pour the lemon-herb dressing over the chicken and vegetables, tossing thoroughly until every piece is well-coated.
Spread the mixture out onto the prepared sheet pan in a single, even layer to ensure everything roasts properly.
Roast in the center of the oven for 18 to 22 minutes, or until the chicken is cooked through and the vegetables are tender with lightly browned edges.