In a large stockpot, combine 1 gallon of water, 1 cup kosher salt, ½ cup sugar, smashed garlic, quarter onion, black peppercorns, rosemary, thyme, whole cloves, and mustard seeds (if using).

Bring the mixture to a boil over medium heat, stirring occasionally to dissolve the salt and sugar.

Once boiling, remove the pot from the heat and allow it to cool completely.

Once cooled, transfer the brine to a large container that can fit the turkey. Add enough cold water to submerge the turkey completely.

Remove the giblets and neck from the turkey (if included).

Place the turkey into the brine solution, ensuring the bird is fully submerged. You can weigh it down with a plate or bowl if necessary.

Cover and refrigerate the turkey for 12-24 hours. The longer it brines, the more flavorful it will be.

After brining, remove the turkey from the brine and pat it dry with paper towels, ensuring the skin is as dry as possible for crispiness.

Preheat the oven to 325°F.

Place the turkey on a roasting rack in a large roasting pan.

Stuff the turkey cavity with quartered onion, rosemary, thyme, smashed garlic, and lemon halves.

Brush the turkey skin with melted butter and season with salt and pepper to taste.

Tie the turkey legs together with kitchen twine and tuck the wings underneath the bird.

Roast the turkey in the preheated oven for about 3 hours, or until the internal temperature reaches 165°F in the thickest part of the thigh (avoid touching the bone).

Baste the turkey with the melted butter every 45 minutes to keep it moist and enhance the golden color.

Once the turkey is done, remove it from the oven and let it rest for 20-30 minutes before carving. This helps the juices redistribute and ensures a moist bird.