Preheat your oven to 375°F and shake 1 tablespoon of all-purpose flour inside a large oven roasting bag to coat the inside, then set aside.
In a large bowl, combine quartered small red potatoes, medium carrot pieces, and large yellow onion wedges; drizzle with 1 tablespoon olive oil and season with 0.5 teaspoon salt, 0.25 teaspoon black pepper, 0.5 teaspoon garlic powder, and 0.25 teaspoon onion powder, then toss to coat.
Pat the whole chicken dry with paper towels. In a small bowl, mix remaining 1 tablespoon olive oil, 0.5 teaspoon salt, 0.25 teaspoon black pepper, 0.5 teaspoon garlic powder, 0.25 teaspoon onion powder, dried thyme, and paprika. Rub this mixture all over the chicken.
Place the seasoned chicken into the prepared oven roasting bag and arrange the seasoned vegetables around it, ensuring even distribution.
Seal the bag with the provided tie, leaving space for steam. Cut 4–6 small slits in the top of the bag to vent.
Place the bag in a large roasting pan and bake for 1 hour 15 minutes to 1 hour 30 minutes, or until the thickest part of the chicken reaches 165°F and the vegetables are tender.
Remove the pan from the oven and let the bag rest for 10–15 minutes. Carefully open the bag, transfer chicken and vegetables to a platter, and discard the bag.