Taken from the excellent guide from Serious Eats
Set water bath to 138 degrees Fahrenheit (59 C)
Cook for 1 hour
Preheat oven to 400 degrees Fahrenheit (200 C)
Season skin and lay flat in between two sheets of parchment paper on top of a sheet pan, then stick another sheet pan on top, forming a sandwich
Bake for 30 to 45 minutes