Take your steak out of the fridge and let it sit at room temperature for about 30 minutes. Dry it off with a paper towel. Preheat a large cast iron skillet over medium-high heat.
Season both sides of the steak generously with kosher salt and coarse ground black pepper. Be sure that the sides are well coated with salt and pepper as well. Set aside. (You want to use about 1 teaspoon of kosher salt per pound of meat.)Note: The steak can be stored uncovered, in the fridge for up to 48 hours before cooking to dry age it, which ensures lots of extra flavor in the meat. Add 1 tablespoon of avocado oil to the hot skillet. Carefully place the seasoned steak in the hot skillet. Don't move it for about 2-3 minutes to develop a nice crust on one side. If you look at the side of the steak, and when you see that the steak is beginning to brown one-third - halfway up the side of the steak, it's ready to flip, one side of the steak should have a nice crust.
Once you have a nice sear on the second side, use your tongs to flip the steak up on its side (where the fat cap is). Hold it upright in the pan for about a minute or two, moving it every 30 seconds or so to ensure all sides are hit. Once you have cooked the sides of the steak, return it flat in the pan, and cook until the steak is about 10-15°F away from your desired temperature. (We were aiming for a medium-rare which is between 125°F-130°F, so for us we began basting the steak with butter at 115°F.
If desired, add 1 tablespoon of butter and the rosemary sprigs to the skillet. Tilt the skillet slightly and use a spoon to baste the steak with the melted butter and aromatics for added flavor. Continue cooking until you're 5°F away from your desired target temperature when you insert a digital thermometer into the thickest part of the steak, then remove it from the pan and let it rest!
Allow the steak to rest for about 5-10 minutes to allow the juices to redistribute before cutting into it.
Top with your favorite buttery dipping sauce and serve with your favorite sides. Enjoy!
Store leftovers in an airtight container in the fridge for up to 5 days. We don't recommend freezing. To reheat the ribeye, carefully heat it in a pan with a little extra oil or butter. Keep in mind that the steak will cook further every time you reheat it. Using the microwave, or a lower heat (350°F) in the air fryer, or in the oven are also options. If using the microwave, set it to 50% power to avoid cooking it too fast.