Preheat your oven to 450°.

Drizzle the olive oil onto a baking sheet with a lip.

Add the vegetables and turkey wings to the baking sheet.

Roast in the oven for 15 to 20 minutes, then reduce the heat to 350° and roast until the turkey wings are golden brown, about another hour, checking occasionally to make sure that the veggies are not sticking to the baking sheet.

You can add water to help loosen everything.

Remove the pan from the oven and let cool slightly.

Scrape everything into a large pot or Dutch oven and place on the stove. Add wine and simmer over medium heat until most of the liquid cooks away, about 5 minutes. Cover the vegetables and turkey wings with water, about 1 quart.

Bring the liquid to a boil over medium-high heat and then reduce the heat to medium-low.

Simmer the stock until it reduces by half, about 1 hour.

Pour the stock through a wire mesh colander and into a medium-sized bowl. Use the back of a spoon to push the turkey and veggie pieces into the bottom of the colander to squeeze out all the juices.

Place the bowl with the stock in the fridge to chill for at least one hour or up to several days. (You can sift through what remains in the colander and gather enough turkey meat for a couple of yummy hot turkey sandwiches if you like!)

Remove the bowl from the fridge.

Use a large spoon to skim and discard any thin layer of fat from the top.

Transfer the stock to a saucepan and slowly bring to a boil over medium heat.

Whisk together 2 tablespoons cornstarch with 2 tablespoons water.

As the stock slowly boils, stir in the cornstarch slurry. The gravy will begin to thicken. You can add as much slurry as you like to get your desired gravy consistency.

Reduce the heat to low and let the gravy simmer slowly.

Season the gravy with sage, salt, and pepper, adding just a bit at a time and tasting while you stir.