1. 1. Prepare Your Oven and Pan: Preheat your oven to 400 F (200 C). Line a large baking sheet with parchment paper for easy cleanup. This step is crucial to prevent sticking and make washing up a breeze.

2. 2. Chop Chicken and Vegetables: Cut the boneless, skinless chicken breasts or thighs into roughly 1-inch pieces. Chop the broccoli into florets, and the red and yellow bell peppers into 1-inch pieces. Cut the red onion into wedges. Aim for uniform sizes so everything cooks evenly.

3. 3. Combine and Season: In a large bowl, combine the chopped chicken, broccoli florets, bell pepper pieces, and red onion wedges. Drizzle with olive oil, then sprinkle with Italian seasoning, garlic powder, salt, and black pepper. Toss everything together until the chicken and vegetables are evenly coated with the oil and seasonings.

4. 4. Arrange on Sheet Pan: Spread the seasoned chicken and vegetables in a single layer on the prepared baking sheet. Ensure there’s enough space between the pieces so they can roast and caramelize rather than steam. If your pan is too crowded, use two sheet pans.

5. 5. Bake Until Cooked: Place the baking sheet in the preheated oven and bake for 15-20 minutes. The chicken should be cooked through, reaching an internal temperature of 165 F (74 C), and the vegetables should be tender-crisp with slightly browned edges. You can give the pan a gentle shake halfway through cooking to promote even roasting.

6. 6. Serve Immediately: Once cooked, remove the sheet pan from the oven. Garnish with fresh chopped parsley, if desired, for a pop of color and freshness. Serve hot and enjoy your quick and healthy dinner!