1. Preheat Your Oven and Prepare the Pan: Start by preheating your oven to 400 F (200 C). Line a large rimmed baking sheet with parchment paper for easy cleanup. This step is crucial for preventing sticking and making post-dinner tidying a breeze.

2. Chop All Your Vegetables: Wash and chop all your vegetables: quarter the small red potatoes, cut the broccoli into florets, seed and cut the bell peppers into 1-inch pieces, and cut the red onion into wedges. Aim for roughly uniform sizes so everything cooks evenly.

3. Prepare the Chicken: Cut the boneless, skinless chicken thighs or breasts into 1-inch pieces. This size ensures the chicken cooks through at the same rate as the vegetables, preventing any dry spots.

4. Combine and Season: In a large bowl, combine the chopped chicken, potatoes, broccoli, bell peppers, and red onion. Drizzle everything with olive oil and fresh lemon juice. Sprinkle with dried oregano, garlic powder, salt, and black pepper. Toss well with your hands or a large spoon until all ingredients are evenly coated.

5. Arrange on the Baking Sheet: Spread the seasoned chicken and vegetables in a single layer on the prepared baking sheet. It’s important not to overcrowd the pan; if necessary, use two baking sheets to ensure everything roasts rather than steams. This allows for better caramelization and a more delicious result.

6. Roast Until Cooked Through: Bake for 25-30 minutes, or until the chicken is cooked through (internal temperature reaches 165 F (74 C)), and the vegetables are tender and slightly browned. You can gently stir the mixture halfway through cooking to promote even browning.

7. Garnish and Serve: Once cooked, remove the pan from the oven. Garnish with fresh chopped parsley, if desired, and serve immediately with extra lemon wedges on the side for an added burst of freshness.