Step 1

Rinse the turkey well inside and out under cold running cold water. Set on a rack set over a rimmed baking sheet. Remove any excess fat or pin feathers and pat dry with paper towels.

Step 2

In a small bowl, add kosher salt and baking powder and stir to combine. Sprinkle the salt mixture over the bird. Coat well, stopping before a crust forms (you may not need all of the salt mixture).

Step 3

Transfer the turkey to a rimmed baking sheet and refrigerate, uncovered, for 12 to 24 hours (or loosely cover and refrigerate for up to 3 days).

Step 4

Remove the turkey from the refrigerator and let sit at room temperature 2 hours prior to roasting.

Step 5

Preheat the oven to 425 degrees and place a rack in the lower third of the oven. In a small bowl, stir together the melted butter and olive oil (for basting) and set aside.

Step 6

Using paper towels, dry both the inside and outside of the turkey. Gently slide your fingers between the skin and the breast of the turkey to loosen the skin. Spread half of the softened butter between the breast and the skin.

Step 7

Arrange twelve sage leaves evenly between the skin and the breast. Place the remaining sage in the cavity. Season with black pepper, including the cavity.

Step 8

Truss the turkey, place the bird on it's back, and rub the remaining 2 tablespoons softened butter all over. Place in a roasting pan breast-side up. Pour 1 inch water into the bottom of the roasting pan. Lower the oven temperature to 325 degrees. Roast the turkey for 3 to 3 1/2 hours, basting every hour with the butter and oil mixture. Add additional water to the pan as needed.

Step 9

Begin testing for doneness after 2 1/2 hours. A thermometer inserted into the thickest part of the thigh should reach 165 degrees, and the juices should run clear.  Transfer the turkey to the carving board and tent with aluminum foil and allow to rest for 30 minutes.

Step 10

Place the roasting pan with drippings over 2 burners and turn heat to medium-high. Add broth and bring to a simmer, scraping up the browned bits off the bottom of the pan.

Step 11

Pour the contents through a fine-mesh strainer set over a large bowl. Using a large flat spoon, skim off and discard the layer of fat that floats to the surface, or pour the liquid into a fat separator and pour off the liquid, leaving the grease behind.

Step 12

Transfer the liquid to a saucepan, place over medium-high heat, and simmer briskly. In a small bowl, add some of the liquid and the cornstarch and whisk together to make a slurry. Gradually whisk the slurry into the simmering liquid, then cook until the gravy thickens, about 5 minutes. Season to taste with salt and pepper.

Step 13

On a large cutting board, place the turkey breast side up. Remove the truss. Begin carving one side of the turkey completely before moving on to the other side.

Step 14

Removing the wing: Pull the wing away from the body and slice through the skin to locate the shoulder joint. Cut through the joint to remove the wing.

Step 15

Removing the whole leg: Pull the leg away from the body and slice through the skin to locate the thigh joint. Cut through the joint to remove the entire leg.

Step 16

Separating the thigh and leg: Cut through the joint that separates the drumstick from the thigh. Serve these pieces whole, or carve them by cutting off the meat in thin slices parallel to the bone.

Step 17

Removing the breast: Cut along the breastbone while following the curvature of the bones. Using your hand or a carving fork, gently pull the breast meat away while using the knife to remove the meat from the ribs. Place turkey breast on the cutting board. For larger slices, slice the breast meat on an angle.

Step 18

Repeat with the second side of the turkey. Arrange cut portions on a serving platter and pass the gravy separately.