Foolproof Thanksgiving Turkey - Ohio Turkey

Ingredients

• One 15 lb. turkey
• 3 tablespoons kosher salt (do not substitute fine salt)
• 3 teaspoons baking powder
• 2 teaspoons dried rosemary
• 2 teaspoons dried parsley
• 2 teaspoons dried thyme
• 3 carrots, chopped into large pieces, divided
• 3 celery stalk, cut into pieces, divided
• 6 whole, peeled garlic cloves, divided
• 1 large onion, cut into large chunks
• 3 sprigs each of fresh rosemary, sage and thyme
• 1 apple, cut into wedges
• 1 orange, cut into wedges
• 1 stick unsalted butter (1/2 cup), sliced
• 5 cups chicken stock, divided