Preheat your oven to 400°F (200°C). Line a large baking sheet with parchment paper for easy cleanup.
In a large bowl, toss the quartered red potatoes with 1 tablespoon of olive oil, salt, and pepper. Spread them in a single layer on one side of the prepared baking sheet. Roast for 15 minutes.
While the potatoes are roasting, prepare the chicken and remaining vegetables. In the same bowl (no need to wash!), add the chicken pieces, broccoli florets, red onion wedges, and cherry tomatoes. Add the remaining olive oil, fresh lemon juice, oregano, thyme, garlic powder, paprika, salt, and pepper. Toss everything together until well combined and the chicken and vegetables are evenly coated.
After the potatoes have roasted for 15 minutes, remove the baking sheet from the oven. Add the seasoned chicken and vegetable mixture to the other side of the baking sheet, spreading it into a single layer. Ensure everything has some space to roast and not steam.
Return the baking sheet to the oven and roast for another 20-25 minutes, or until the chicken is cooked through (internal temperature reaches 165°F or 74°C) and the vegetables are tender and slightly caramelized.
Once cooked, remove from the oven. Garnish with fresh chopped parsley before serving.