Place the thighs, skin side down, in a cast iron pan and heat on low until they start to sizzle. Cook for 5-10 minutes, until skin has browned.
Remove from the pan and set aside to cool slightly.
Once cool enough to handle, place the turkey thighs in a vacuum sealable bag (or ziplock freezer bag of using the water displacement method described above) along with the duck fat, sage, garlic, apple and paprika.
Vacuum seal the bag and cook in a 150F degree sous vide water bath for 12 hours.
Remove the bag from the sous vide cooker. Open the bag and remove the turkey thighs.
Strain the bag juice and reserve for the gravy.
Heat a cast iron skillet over medium heat and add the thighs, skin side down. Cook for 3-5 minutes, until the skin is golden and starts to crisp.
Remove and serve with turkey gravy (below).
Turkey Gravy:
Heat the butter and flour in a skillet over medium heat. Whisk until a light roux forms, about 1 minute.
SLOWLY whisk in the bag juice, ensuring you whisk constantly to avoid lumps from forming.
Once the juice is whisked in, remove from heat and serve over the turkey. (Add additional pepper to the gravy if you like it peppery.)
Notes
Removing air from the sealable bag is essential for food safety as it keeps bacteria out of the bag.
The turkey thighs need to stay submerged in the water bath in order to cook safely and properly. If they start to float, you can open the bag to let the excess air out, then reseal it. (This works for a vacuum sealed bag or a ziploc bag).
You can also prevent floating by using a sous vide sinker weight or weighing the bag down with something heavy like a wet towel.
If you use other cuts of turkey for this recipe like legs or breasts, just remember that they all have different cooking times and you may need to adjust the temperature of your water bath.
Instead of duck fat, you can use butter or bacon fat.
To ensure a crispy skin, don't move the thighs around while they’re browning in the skillet.
Be careful not to brown the turkey thighs for too long as they may start to dry out. Just 3-5 minutes should get the skin nice and crispy.