Preheat your oven to 400°F (200°C) and line a large rimmed baking sheet with parchment paper for easy cleanup.
Slice the zucchini into half-moons and chop the red bell pepper into one-inch bite-sized pieces.
Place the chicken breast in the center of the baking sheet and arrange the zucchini and peppers around it in a single layer.
Drizzle the olive oil and fresh lemon juice evenly over the chicken and the vegetables.
In a small bowl, combine the rosemary, thyme, garlic powder, onion powder, and black pepper, then sprinkle the mixture over everything.
Toss the vegetables to coat and rub the herb mixture into the chicken breast on both sides.
Roast in the oven for 20 to 25 minutes, or until the chicken reaches an internal temperature of 165°F and the vegetables are tender and slightly caramelized.
Remove from the oven and let the chicken rest for 5 minutes before slicing to ensure maximum juiciness.