Who doesn't love a good medium-rare steak? We employ our sous-vide machine to make the perfect steak, sealing it with aromatic herbs and garlic before cooking it in its own juices. As soon as you try this method, you won't want to cook steak any other way.
When we tested this recipe, we made two steaks: one we cooked for one hour and the other for two. Since the temperature cannot exceed 131℉(55℃) , you don't have to worry about the steak overcooking, and the flavors of the aromatics will infuse the meat. If you're in a pinch, however, the one-hour steak is still incredible and miles above your average steak.
1. Season the steak liberally with salt and pepper. Place in a vacuum-seal bag with the thyme, garlic, rosemary and lemon and vacuum seal closed. Alternatively, place the ingredients in a sealable plastic bag and dip the bag into a large bowl of water to displace the air before sealing shut.
2. Preheat a pot of water fitted with a sous-vide immersion circulator to 131℉(55℃) according to the manufacturer's directions. Cook the steak for 2 hours, making sure it is completely submerged in the water. Remove the bag from the pot and take the steak out of the bag, drying with paper towels.
3. In a large cast-iron skillet, heat the vegetable oil over high heat. Add the steak and cook, flipping once until seared on both sides, about 1 minute per side. Add the butter and baste the steak for 10 to 15 seconds more. Transfer to a board to rest for 5 minutes.
4. Slice the steak and garnish with flaky sea salt, then serve.