When you remove the innards from the cavity of the turkey, place them in a pot or crockpot. Cover with water and bring up to a boil. Reduce to a simmer while the turkey roasts. Add more water if needed to keep everything covered.

When the turkey is done and resting, pour the drippings into a fat separator or a jar/bowl that will allow you to scoop off the fat easily.

This scooped off fat can be used in place of the butter.
Also, if you prefer a thick gravy, double the amount of fat and flour for the roux. Double the whole recipe if you have a lot of drippings and broth from the innards.

Melt the butter/fat in a saucepan over medium heat. Sprinkle in the flour while whisking. Reduce the heat, whisk until it smells slightly nutty or the color begins to deepen to brown. Whisk in the white wine rapidly as it thickens.

Next rapidly whisk in the warm drippings and strained broth from the innards into the gravy. Constantly whisk until it begins to thicken and the clumps are smoothed out.

Once it simmers, reduce the heat to low. Add salt and black pepper if desired- but taste first. A brined turkey will usually let off very salty drippings.

If you get to the end of making the gravy and it seems too thin, whisk together flour & cold water (broth or wine work too). Whisk this flour-liquid in and simmer for an extra 3-6 minutes until it is thick and tasty.