- Preheat a sous vide cooker to 60°F. Once the steak is thawed, open the package and remove the meat from the bone with a knife, cutting very closely along the bone where it’s attached.
- Season the steak generously with salt and pepper. Place in a ziplock sous vide bag along with garlic, butter, olive oil, rosemary, thyme, sliced fennel, and chopped shallot bulbs; distribute evenly. Seal the bag and place in the sous vide water bath.
- Keep the sealed bag in the sous vide at 60°F for 3 hours. Boil one cup of water on the stove and add in the sugar and citrus (lemon and orange zest). In the meantime, wash the rhubarb stalk and trim off the ends, then cut them into about 1x1 inch pieces.
- Put the cut rhubarb in a medium-sized bowl and pour the hot water mixture on it, then seal with plastic wrap and let sit. Next, boil water with salt and add the fingerling potatoes, letting cook for about 15 minutes (or until potatoes become tender; use a fork to test). Once tender, remove the potatoes from the pot with a strainer, and add them to cold water to cool down.
- Take the steak out of the sous vide machine at least one hour before cooking. Gently lower the steak into a cast iron skillet on medium heat and add a tablespoon of extra virgin olive oil. Then after 15 to 30 seconds, flip steak so that the second side comes into contact with the pan. Add all the flavors from the bag, sear the steak on both sides and place on a resting rack.
- In the same cast iron skillet, add the remaining lemon, butter, olive oil and herbs as desired. Then add the smashed fingerling potatoes, let them cook until crispy on both sides and season with maldon salt and fresh ground black pepper.
- Serve the steak with fingerling potatoes, sliced cherry peppers, rhubarb and mixed herbs.