Set the oven to 170 F, or the lowest possible temperature. This will take a while, depending on the size of the cut.

Some recipes suggest rubbing the beef with a garlic clove, but I just don't see the point.

Sprinkle some kosher salt on the outside of the meat, on all sides, and place the beef on a roasting rack, and put the rack in a roasting pan. I recommend putting a small amount of water in the pan, so the drippings won't burn.

I strongly recommend a thermometer that can be left in the meat and the display outside the oven. Set it for around 140 F. You can adjust this based on how well-done you want the meat. I recommend about 10-15 degrees below your final temperature.

When the alarm goes off, the meat is delicious and nearly finished. For some extra flavor (and to finish the cooking), turn the oven onto broil and let the outside brown and crust until you're happy with the look of the outside and the temperature on the inside.

Cover with aluminum foil and let it rest. Carve across the grain to serve. Ideally the original cut will be with the grain, so you can cut thick steaks off. If you've done it medium or rare, and someone wants it well-done, you can finish their meat in a hot pan, giving it a nice browning and crust.