Roasted Turkey with Gravy

Ingredients

• 2 qt cold water
• 1 large onion
• 1 bunch fresh thyme
• 3/4 cup sea salt
• 1 turkey (15 lb)
• 5 qt cold water
• 2 qt ice
• 1/2 lb unsalted butter
• 1/2 tsp sea salt
• 1 tsp freshly ground black pepper
• 2 tsp fresh thyme
• 1 onion
• 1 large carrot
• 1 rib celery
• 2 lb chicken bones
• 4 tbsp vegetable oil
• 1 cup dry white wine
• 6 cups stock (turkey or chicken)
• 1 tsp sea salt
• 1/2 tsp freshly ground black pepper
• 1/2 head f