Curtis Stone | Roasted Turkey and Pan Gravy for Giving Thanks

Ingredients

• 6 quarts cold water, divided
• 1 cup kosher salt
• 1 cup packed golden brown sugar
• 1/2 cup Cajun Spice Mix (see recipe)
• 3 sprigs fresh rosemary, divided
• One 14- to 16-lb whole turkey
• 2 onions, coarsely chopped
• 2 green bell peppers, coarsely chopped
• 3 celery stalks, coarsely chopped
• 12 tbs (1 1/2 sticks) unsalted butter, divided
• 3 cups (about) reduced-sodium chicken stock
• 1/4 cup unbleached all-purpose flour