Preheat the sous vide machine: Add water to the sous vide container or a large pot, set the Sous Vide Precision Cooker to (135°F/57°C) for medium-rare doneness. If you’d like to cook it less, see the guide in the post.
Season the steak: Rub the steak with 1/2 tablespoon oil on all sides.
Season both sides with salt and pepper.
Sous vide the steak: Add the seasoned porterhouse 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. Then seal the rest of the bag.
Place the bag into the water bath in the sous vide container. Make sure it is fully submerged.
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.
Sear the steak: Remove the steak from the bag and wipe off the moisture with paper towels (Make sure the surface of the steak is completely dry before searing).
Season with more salt and pepper if necessary.
Place the cast-iron skillet on medium-high heat. Add the remaining olive oil. When very hot, add the minced garlic and steak and sear about 1 minute per side.
Cut the meat away from the bone and slice across the grain into strips. Then serve with potatoes and veggies.