The basics from our butcher - 500 F and 5 minutes a pound - worked out like this for us, as it was calculated on the weight of the roast.
* Let the meat come to room temperature for about 2 hours.
* Cleaned the meat and trimmed excess fat.
* Poked a goodly number of holes with a large fork, and about 8 or so with a knife to insert garlic slivers.
* Cleaned the garlic and took about half and sliced into slivers to insert in the deeper holes.
* Mixed the ingredients threw in enough extra virgin olive oil to make a mud, and mixed it all up - slathered it on the roast.
* Placed meat fat side up in roasting pan with about 3 inch sides, and a rack.
* Added just enough water to cover bottom of pan to reduce splashing of drippings.
* Preheated oven to 500 F
* Calculated 41 minutes for my roast. Your time will vary. Take weight of roast and multiply times 5 to get minutes.
* Insert the meat thermometer and shut that door! (We used an inexpensive Taylor digital that had a cable to monitor temp of meat without opening the door).
* Turn off the oven at YOUR scheduled time (remember that weight times 5 equals total minutes).
* Check the temperature after exactly 2 hours. Do NOT open the door even once during this time.
It came out with meat temp at 135, which is Medium Rare, but it continues to finish cooking, as you leave covered with foil for 25 minutes of resting time out on the kitchen counter.
* De-boned it as this YouTube video shows:.
Optional: MaKe au jus after the roast was done by taking three tablespoons of fat drippings, all the carmelized bits that fell into the bottom of roasting pan, two tablespoons of flour, 1 quart of beef broth from box, simmered and stirred chunks out on medium, and then strain as poured into gravy boat.
Hope this works out as well for you as it did for us. Just had French Dip sandwiches today made from leftovers. It was great for both meals.