Preheat the oven to 425°F (220°C). Line a large sheet pan with parchment paper or lightly grease it.
In a large bowl, toss the baby potatoes, broccoli florets, and bell peppers with olive oil, minced garlic, Italian seasoning, salt, and pepper.
Spread the vegetables evenly around the edges of the prepared sheet pan, leaving space in the center for the chicken.
In a shallow bowl, combine the grated Parmesan cheese, breadcrumbs, Italian seasoning, garlic powder, salt, and black pepper.
Brush the chicken breasts lightly with olive oil, then press them into the Parmesan mixture until fully coated on all sides.
Place the coated chicken breasts in the center of the sheet pan.
Bake for 25–30 minutes, or until the chicken reaches an internal temperature of 165°F (74°C) and the vegetables are tender.
Broil for 2–3 minutes if desired to create an extra golden Parmesan crust.
Remove from the oven and let rest for 5 minutes before serving.