Preheat your oven to 425°F and line two large sheet pans with parchment paper or aluminum foil for easy cleanup. Divide the chicken pieces between the two pans, spreading them into a single layer without overlapping too much.

In a small bowl, whisk together olive oil, garlic powder, Italian seasoning, paprika, salt, and black pepper until well combined. Drizzle half the seasoning mixture over the chicken pieces and toss to coat evenly, ensuring every piece touches the oil and spices for maximum flavor development.

Roast the chicken at 425°F for 10 minutes before removing the pans from the oven to add vegetables. This head start ensures the chicken stays juicy while vegetables finish cooking in the remaining time.

Add the broccoli florets, bell peppers, zucchini slices, cherry tomatoes, and red onion to each pan around the chicken. Toss the vegetables with the remaining seasoning mixture, distributing them evenly so the loaded sheet pan veggie dinner cooks uniformly without crowding.

Return both pans to the oven and bake for exactly 20 more minutes until chicken reaches 165°F internally and vegetables are tender with slightly caramelized edges. The total cooking time keeps everything from overcooking while achieving perfect doneness throughout.

Remove from the oven and immediately drizzle balsamic vinegar and fresh lemon juice over the sheet pan veggie dinner for brightness and depth. The acids help balance richness while adding sophisticated flavor that elevates this weeknight crowd meal beyond basic roasted vegetables.

Scatter fresh parsley over the top as garnish and serve directly from the pans for a family-style presentation. Let it rest for two minutes before serving to allow juices to redistribute through the chicken and vegetables.