Preheat the oven to 375°F.
Place the chicken in a large bowl or on a large tray to prep. Pat the chicken dry with a paper towel.
Season the chicken with salt, pepper, thyme, oregano, paprika, and garlic powder. Don’t forget inside the cavity.
Stuff the lemon halves inside the cavity.
Heat olive oil and butter in a large Dutch oven over medium heat.
Add the onion, carrots, and celery, and cook for 5–7 minutes until softened.
Stir in the garlic and cook for another 30 seconds.
Place the seasoned chicken on top of the cooked vegetables.
Add the chicken broth and white wine to the pot.
Bring to a gentle simmer, then cover and transfer to the oven. Roast for approximately 1 hour.
Carefully remove from the oven and sprinkle the orzo around the chicken, stirring it gently into the liquid.
Cover and return to the oven for an additional 20–25 minutes, or until the orzo is tender and the chicken reaches an internal temperature of 165°F.
Remove the chicken from the pot and let it rest for 10 minutes.
Stir the orzo and vegetables. If using spinach, stir it in now, letting it wilt in the heat.
Taste and adjust seasoning if needed.
Remove the cooked chicken from the bones and return it to the pot or serve it over the orzo. Sprinkle with fresh parsley before serving.