Preheat your oven to 400°F (200°C) and line a large baking sheet with parchment paper for easy cleanup.
Place the broccoli florets, sliced carrots, and red bell pepper on the baking sheet, then drizzle with half of the olive oil.
Sprinkle the vegetables with half of the sea salt and black pepper, tossing well to ensure even coating.
Roast the vegetables in the oven for 18 to 20 minutes until they are tender and slightly caramelized at the edges.
While the vegetables roast, season the chicken breast on both sides with the garlic powder, dried oregano, and the remaining salt and pepper.
Heat the remaining olive oil in a medium skillet over medium-high heat until shimmering.
Carefully place the chicken in the skillet and sear for 6 to 8 minutes per side, or until the exterior is golden and the internal temperature reaches 165°F.
Remove the chicken from the pan and let it rest for 3 minutes before serving it alongside the roasted vegetable medley.