Preheat your oven to 400°F (200°C) and line a large sheet pan with parchment paper.
Slice the chicken breast into 1-inch strips and chop the broccoli, red bell pepper, and carrots into bite-sized pieces.
In a large mixing bowl, toss the chicken and vegetables with the olive oil, garlic powder, sea salt, and black pepper until everything is well coated.
Spread the chicken and vegetable mixture in a single layer across the prepared baking sheet.
Roast in the oven for 18 to 22 minutes, or until the chicken is cooked through and the vegetables are tender with slightly browned edges.
While the chicken roasts, whisk together the fresh lemon juice, lemon zest, and finely chopped dill in a small bowl.
Remove the pan from the oven and immediately drizzle the lemon-dill mixture over the hot chicken and vegetables, tossing gently to combine before serving.