Preheat your oven to 400°F (200°C) and line a large sheet pan with parchment paper for easy cleanup.
Pat the chicken breast dry with a paper towel to ensure a golden sear and place it on one side of the prepared pan.
In a small bowl, whisk together half of the olive oil, garlic powder, dried oregano, and half of the sea salt and black pepper.
Rub the herb and oil mixture evenly over both sides of the chicken breast until well coated.
In a medium bowl, toss the broccoli florets, bell pepper strips, and cherry tomatoes with the remaining olive oil, sea salt, and black pepper.
Arrange the vegetables in a single layer on the other side of the sheet pan, ensuring they are not overcrowded.
Roast for 20-25 minutes, or until the chicken reaches an internal temperature of 165°F and the vegetables are tender and slightly charred.
Remove from the oven and immediately drizzle the fresh lemon juice and sprinkle the lemon zest over the chicken and vegetables before serving.