Preheat the oven to 450F.

Lay the defrosted meat out on a cutting board and pat dry with a paper down. 

Rub the butter all over the tenderloin and then sprinkle on all of the remaining ingredients, pressing them into the meat. 

Lay the tenderloin in a roasting pan. If it’s too long, fold the thinnest side a bit so it fits. This will help with even cooking, too. 

Cook the tenderloin for 20 minutes at 450F and check the internal temperature. It should be about 125-135F (or medium-rare). If it’s not done yet (and it might not be) drop the oven temperature to 350F and check the internal temperature every 5-10 minutes. The time will vary depending on the thickness of your meat.

Once you reach medium-rare, remove the tenderloin, cover the pan with foil and allow the meat to rest for 10-15 minutes before slicing and serving. 

Slice about 1-2 inch thick pieces and serve!