Pat the steaks dry with a paper towel. Season the steaks with the salt and pepper, and rub it into the beef. Melt the half of butter in a pan over high heat. Place the steaks in a hot pan and cook for 3 ½ minutes.

Add the remaining butter to the pan, and flip the steaks and cook for another 3 ½ minutes. Remove the steak from the pan, and let it rest for 5 minutes. You want the steak to reach 130 degrees. You can check the temperature by inserting a meat thermometer into the middle of the steak. The temperature of the steak will rise about 5 degrees as it rests, and 135 degrees will give you a perfect medium rare steak.

Keep the drippings from the steak in the pan, and add the stone ground mustard, garlic, heavy cream, and thyme to the pan.

Whisk the sauce together and simmer slowly for 5 minutes while the steak rests, then serve the steak with the sauce.