Dry-Brine the Steak

1. Pat the steak dry and season both sides with salt equal to about 1% of the steak’s weight. For a 12 oz (340 g) steak, use about 0.12 oz (3.4 g) of salt, or roughly: 1 1/4 teaspoons Diamond Crystal kosher salt, 3/4 teaspoon Morton kosher salt, or 1/2 teaspoon table salt.
2. Place it on a wire rack over a baking sheet and refrigerate uncovered for at least 1 hour, ideally 2 to 4 hours for deeper flavor and a better crust. If you don’t have an hour, season the steak right before cooking, or salt it after it’s cooked.

Parboil the Potatoes

1. Wash the potatoes and cut them into 1-inch (2.5 cm) pieces. Leave very small potatoes whole. Peeling is optional (I usually leave the skins on).
2. Place the potatoes in a pot, cover with cold water, add about 1 teaspoon salt, and bring to a boil over high heat. Once boiling, reduce the heat to medium and cook, uncovered, until the potatoes are fork-tender, about 10 minutes.
3. Drain well in a colander to remove any excess moisture, then set them aside uncovered until you’re ready to finish them in the pan.

Pan-Sear the Steak

1. Take the steak out of the fridge about 15 minutes before cooking.
2. Meanwhile, if using fresh herbs, chop them and set them aside.
3. Turn on the exhaust fan or open a window. Heat a heavy skillet over medium-high heat for about 3 minutes. Add 2 tablespoons high-heat oil and heat for another minute.
4. Pat the steak dry again and, if desired, season both sides with finely ground black pepper. If the steak has a fat cap, hold it fat-side down with tongs and sear for 60-90 seconds, until browned and crisp. Lay the steak flat and continue cooking, flipping every 30 seconds.
5. After about 3 minutes, start checking the internal temperature. Insert a meat thermometer into the thickest part, away from the bone and large pockets of fat. Remove the steak from the pan when it reaches the pull temperature for your preferred doneness: 110°F (43°C) for rare, 120°F (49°C) for medium-rare, 130°F (54°C) for medium, 140°F (60°C) for medium-well, 150°F (66°C) for well-done. See the complete steak temperature chart above recipe card.
6. Transfer the steak to a plate and let it rest for 5 minutes. While it rests, top with a spoonful of butter if desired. Finish the potatoes while the steak rests.

Pan-Sear the Potatoes

1. Put the same pan back over medium-high heat. Add a little of the same oil you used to sear the steak and let it heat for about 1 minute.
2. Add the potatoes and cook for 6 to 8 minutes, stirring occasionally, until they start to turn lightly golden. Meanwhile, mince the garlic.
3. Once the potatoes are lightly golden, add the garlic and rosemary or thyme and cook for about 1 minute. Add the butter, salt, and pepper, then stir to coat. Cook for another 1 to 2 minutes, until the butter melts and the potatoes are evenly coated.
4. Remove the skillet from the heat.

Slice and Serve

1. Thinly slice the steak and serve with the potatoes while everything is still warm. Sprinkle with chopped parsley, if desired.
2. For cuts like Denver, hanger, skirt, or flat iron, slice against the grain to shorten the muscle fibers and make the meat easier to chew. Naturally tender cuts like filet mignon, ribeye, or strip slice however you prefer.