Preheat the oven to 375°F. Pat the chicken dry and rub it all over with olive oil, salt, and pepper. Place one lemon cut in half and four sprigs of thyme inside the cavity.
Set the chicken in a roasting pan and roast for 60-75 minutes until the internal temperature reaches 165°F in the thickest part of the thigh.
While the chicken roasts, melt 2 tablespoons of butter in a skillet over medium heat. Add the onion and celery and cook until softened. Stir in the bread cubes, remaining thyme leaves, and chicken broth. Transfer the mixture to a baking dish and bake alongside the chicken for the last 25 minutes.
Toss the carrots with the remaining 2 tablespoons of butter, honey, and a pinch of salt. Spread them on a baking sheet and add them to the oven for the final 20 minutes of cooking.
Let the chicken rest 10 minutes before carving. Serve the stuffing and carrots on the side.