Fill a pot with water and preheat your sous vide cooker to desired final temperature, following manufacturer's instructions.

Season the steak and add it to a vacuum bag, along with aromatics (if using). Seal the bag with a vacuum sealing system.

Once the sous vide cooker is preheated, add the sealed bag to the water bath and cook for the desired time (see chart in post for time and temperatures).

Once cooked, remove steak from the water bath, open and pat dry with paper towels.

Preheat a cast iron pan, over high heat, until smoking. Add vegetable oil and sear the steak for about one minute per side. You can add butter at this point, if you wish. You can also add some char to your steak with a cooking torch.

Serve steak immediately.