Preheat your oven to 425°F (220°C).
In a mixing bowl, combine the olive oil, garlic powder, paprika, dried thyme, salt, and pepper to create a marinade.
Add the chicken thighs to the bowl, ensuring they are well coated with the marinade. Let them marinate while you prepare the vegetables.
On the large sheet pan, spread out the broccoli florets, baby carrots, sliced red bell pepper, and sliced onion. Drizzle with a bit of olive oil and season with salt and pepper.
Place the marinated chicken thighs on top of the vegetables on the sheet pan, skin side up.
Roast in the preheated oven for 30 minutes, or until the chicken reaches an internal temperature of 165°F (75°C) and the vegetables are tender and slightly caramelized.
Remove from the oven and let it rest for a few minutes before serving. For an added touch, serve with lemon wedges.