Add water to the sous vide container or a large pot, set the Sous Vide Precision Cooker to (135°F/57°C) for medium doneness. If you’d like to cook to other doneness, see the temperature chart in the post above.
Rub your tbone steak with 1/2 tablespoon oil on all sides. Then season generously with salt and pepper.
Place the seasoned tbone steak to a zip-lock bag together with optional herbs.
Seal all but one corner of the bag, and slowly place it into a container with cold water. Make sure everything below the zip-line is covered by water, and push the air out. Then seal the rest of the bag.
Place the vacuum-sealed bag into the sous vide water bath. Make sure it is fully submerged.
Sous vide cook the steak for 1 hour. If your steak is 2-inch thick, cook it for 1.5 to 2 hours.
When the timer goes off, remove the bag from the water bath and transfer it to the fridge or an ice bath. Let it chill for about 10 minutes.
Remove the tbone from the bag and wipe off the moisture with paper towels. (Make sure to pat dry the surface completely.)
Season with more salt and pepper if necessary.
Place the cast-iron skillet or grill on medium-high heat. Add the remaining olive oil. When very hot, add the steak and sear about 1 minute per side. (If you use grill, you can brush the oil on the steak).
Cut the meat away from the bone and slice across the grain into strips. Serve immediately.