- Preheat the oven to 180 degrees C.
- Melt the butter in a small saucepan. Add the zest and juice of the lemon and 1 teaspoon of thyme leaves to the butter mixture. Set aside.
- Take the giblets out of the turkey and wash the turkey inside and out. Remove any excess fat and leftover pinfeathers and pat the outside dry.
- Place the turkey in a large roasting pan. Liberally salt and pepper the inside of the turkey cavity. Stuff the cavity with the bunch of thyme, halved lemon, quartered onion, and the garlic.
- Brush the outside of the turkey with the butter mixture and season with salt and pepper.
- Tie the legs together with string and tuck the wing tips under the body of the turkey.
- Roast the turkey about 2 1/2 hours, or until the juices run clear when you cut between the leg and the thigh. Remove the turkey to a cutting board and cover with aluminum foil, letting it rest for 20 minutes.
- Slice the turkey and serve.