Remove the steaks from the fridge and dry them off with a paper towel on all sides. Season generously with Kosher salt on both sides, then rub the steaks with dry rub on all sides. Leave them out for 40 minutes or so, until they come to room temp. See note below for an alternative, more time consuming option that yields even more flavor from your dry rub!
Once the steaks have reached room temp (or just slightly cooler than room temp) put a skillet on the stove and turn the heat on high. Let it heat for about 1 minute, then season it generously with oil.
When the oil is shimmering or just about to smoke, place the steaks fat side down onto the pan. Cook for 1-2 minutes to render the fat as much as possible.
Sear the steaks for 3 minutes on each side, until a deep golden brown crust is formed on both sides. With tongs, turn the steak on its edge to give the same golden brown sear as the top and bottom. Do this with all sides. Reduce the heat to medium low, then add 2 tbsp of unsalted butter to the pan. Carefully tilt the pan towards you to create a pool of melted butter. With a spoon, baste the steaks for 1 minute. Baste = spoon melted butter over the top of the steaks.
Take the internal temp of the steak. If it's below 125 degrees F, keep them in the pan at medium low heat, flipping every minute until the internal temp reaches 125-130 degrees F.
Remove the steaks from the pan and let them rest for 10 minutes.
As the steaks rest, adjust the heat back to medium high heat. If the pan is dry, add 1 tbsp of butter. Add the mushrooms to the pan and season generously with a pinch of salt. Cook for 2-3 minutes until golden brown, then flip them and continue to cook for another 2 minutes until the other side is golden brown. Add the shallots and cook for another 1-2 minutes or so. Pour a generous splash of wine into the pan and toss together with the mushrooms. Add the thyme and let the wine cook off for 2 minutes. Remove the mushrooms from the heat.
Cut the steak against the grain and plate it. Top with mushrooms or put the mushrooms on the side. Pour any excess wine/jus from the pan onto the steak. Enjoy immediately!