Season the Rib Eye Steak (200 gram) with Maldon® Sea Salt Flakes (to taste) and Freshly Ground Black Pepper (to taste).
Fill a pot with water and fasten the sous vide machine to the side. Let the water come up to 129 degrees F (54 degrees C).
Place the steak in a plastic ziplock bag with Fresh Rosemary (to taste). Remove as much air as you can. Clip the bag to the inside of the pot once the water has come up to temperature. Let cook for 1 hour.
Remove the steak bag from the water. Sear the outside of the steak in a very hot cast iron pan with Butter (to taste) to get a nice crust. Season with additional Maldon® Sea Salt Flakes (to taste) if desired.
Serve right away! No need to rest sous vide steak.