Heat a skillet over medium high heat and add 1 tablespoon of cooking oil.
Add the turkey legs and brown on both sides.
Remove and let cool.
Add the turkey legs with the remaining ingredients (except the cooking oil) to a vacuum sealable bag (or zip lock freezer bag if using the water displacement method) and seal.
Place in the water bath and cook for 24 hours.
Remove and place in an ice bath for 10 minutes.
Heat a skillet over medium high heat and add 1 tablespoon of cooking oil.
Remove the turkey legs from the bag, reserving the cooking liquid.
Brown the turkey legs again on each side (about 2 minutes) to crisp the skin.
Simmer the cooking liquid over medium high heat for 2-3 minutes. To thicken, slowly whisk in a cornstarch slurry (1 tablespoon of water mixed with 1 tablespoon of cornstarch).
Serve the turkey legs drizzled with the reserved bag sauce and more fresh sage.
Notes
Removing air from the sealable bag is essential for food safety. This will keep bacteria out of the bag, which is especially important when cooking for long periods of time.
As the turkey legs cook for 24 hours in the water bath, you’ll want to check on the water level as some evaporation may occur. If it does, just top up the bath with more water.
Check on the turkey legs to make sure the bag doesn’t start floating in the water bath. If the bag floats, just open it, let the excess air out and reseal it.
When browning the turkey legs at the end, make sure you only do so for about 2 minutes per side. Any longer and the skin could burn and the legs may start to dry out.
The turkey skin may still be rubbery even after browning. If you prefer, you can just remove the skin and skip the second browning.
If you don't have any duck fat, you can use butter or bacon fat instead.