First things first. Preheat your oven to 425°F (220°C). While that’s heating up, you can prepare the rest of the ingredients. A hot oven ensures those veggies caramelize nicely.

In a large mixing bowl, combine the olive oil, garlic, smoked paprika, Italian herbs, salt, pepper, and lemon zest. Whisk them together until well-blended. A good marinade is essential. Trust me; it makes all the difference.

Add the chicken chunks to the marinade, making sure each piece is evenly coated. Let it sit for about 10 minutes. This step allows those flavors to penetrate the chicken, enhancing its taste.

While your chicken marinates, chop up the vegetables. The onion, bell peppers, zucchini, and broccoli should all be cut into bite-sized pieces. This not only aids in even cooking but also makes for easy eating.

Spread the marinated chicken evenly over a large sheet pan. Add the chopped vegetables around the chicken. Don't overcrowd the pan; we want them all to have space to roast properly.

Pop the sheet pan in your preheated oven and bake for about 25-30 minutes. You’re looking for that golden-brown color on the chicken and softened veggies. An instant-read thermometer should register at least 165°F (74°C) when the chicken is properly cooked.

Once done, take the pan out. Sprinkle the grated Parmesan over the chicken and veggies. Let it rest for a few minutes. To serve, garnish with freshly chopped parsley for that bright touch.