Set sous vide machine to 74C/165F.
Generously season pork belly with salt. Place pork in freezer bag, and remove the air through a vacuum sealer or the displacement method. Drop the bag in the bath for 10 hours.
Remove bag from bath. Take pork belly out of the bag, pat dry with paper towels and season with salt and pepper (or seasoning) to taste.
Heat up large skillet on high and add oil. Sear pork belly fat side down for 2 to 3 minutes, or until crispy. Flip and sear each side for one minute. Remove from pan, and place on a plate to rest for 5 minutes. Once rested, slice, serve and enjoy!