Preheat your oven to 400°F (200°C) and line a large rimmed baking sheet with parchment paper.
Pat the chicken breast dry with a paper towel and slice it into even 1-inch strips for uniform cooking.
In a large mixing bowl, combine the chicken strips, broccoli florets, bell pepper strips, and sliced carrots.
Drizzle the olive oil and lemon juice over the mixture, then sprinkle with dried oregano, garlic powder, sea salt, and black pepper.
Toss everything together until the chicken and vegetables are thoroughly coated in the oil and seasonings.
Spread the mixture in a single layer on the prepared baking sheet, ensuring the pieces are not overcrowded.
Roast for 18 to 22 minutes until the chicken is cooked through and the vegetables have developed slightly charred, caramelized edges.
Remove from the oven and serve immediately while hot.