Preheat your oven to 400°F and line a large 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 small florets and slice the red bell pepper into 1-inch pieces, adding them to the bowl with the chicken.
In a small jar or bowl, whisk together the extra virgin olive oil, fresh lemon juice, garlic powder, dried oregano, sea salt, and black pepper.
Pour the lemon-herb marinade over the chicken and vegetables, tossing thoroughly to ensure every piece is well-coated.
Spread the mixture in a single, even layer on the prepared baking sheet, making sure not to overcrowd the pan so the vegetables roast rather than steam.
Roast in the oven for 18 to 22 minutes, or until the chicken is cooked through and the vegetables are tender with slightly caramelized edges.
Remove from the oven and garnish with freshly chopped parsley before serving hot.