Step 1

Before cooking, be sure that your oven is VERY clean to prevent smoking. Preheat the oven to 450°F and set an oven rack in the lowest position.

Step 2

Remove and discard truss that holds turkey legs together. Trim off and discard any excess fat in the neck or body cavity. Remove giblets and neck; discard or save for stock.

Step 3

Rinse the turkey inside and out with warm water. Pat dry with paper towels. Place a V-shaped rack in a 13 x 16 x 3-inch heavy stainless-steel roasting pan. (Do not use a dark roasting pan or a disposable aluminum pan.) Rub the turkey skin all over with the olive oil and sprinkle with the salt and pepper. Set the bird breast-side-up on the rack. Pull the wings away from the body, then firmly twist them to push the wing tips under the bird. Using aluminum foil, form caps over the tips of the end of each drumstick. (Do not tie the legs together, add stuffing, or close the body cavity.) Insert a digital leave-in meat thermometer near the center of the breast through the thickest part until the tip touches the bone.

Step 4

Turn on your exhaust fan and crack a kitchen window. Place the turkey in the oven and roast, without basting, until the thermometer reaches 160°F, 1 to 1½ hours. If your oven has hot spots, rotate the pan halfway through cooking to assure even browning. (If at any point your kitchen gets unbearably smoky or the fat is spitting, pour a cup of tepid water in the roasting pan. Just keep in mind that the liquid will create steam in the oven, so the skin won't be quite as crispy.)

Step 5

Remove the pan from the oven. Using clean oven mitts (that you don't mind getting dirty), carefully tilt the turkey so that the juices from the cavity run into the roasting pan. Transfer the turkey to a platter or cutting board (do not clean the roasting pan), tent the turkey with foil, and let it rest for 20 to 30 minutes. This will allow the internal temperature to reach at least 165°F (the USDA safe-cooking temperature for turkey) and the juices to settle.

Step 6

While the turkey rests, make the gravy: Place the roasting pan on a burner on your stove. (Be very careful handling the pan; it's easy to forget that it's hot.) Skim away any excess fat or solids that have accumulated in the pan. Add the broth and cook over medium heat, scraping the bottom of the pan with a whisk or wooden spoon to loosen any brown bits, until simmering. Turn off the heat and set aside.

Step 7

In a medium sauce pan, melt the butter over medium-low heat. Add the onions and cook until very soft and translucent, about 15 minutes. Do not brown. Whisk in the flour and cook for 2 to 3 minutes, stirring occasionally. Whisk in the turkey dripping-chicken broth mixture and Cognac and cook, uncovered, stirring occasionally, for about 5 minutes or until thickened. Stir in the cream (if using) and chopped herbs. Taste and adjust seasoning with salt and pepper, if necessary. Transfer to a gravy bowl.

Step 8

Carve the turkey and serve with the gravy on the side.