Early in the morning preheat oven to 500 degrees F. (8:00-9:00 AM)
Lay the roast in a large roasting pan bone side down.
In a small bowl mash together garlic, horseradish, thyme, rosemary, salt, pepper, flour and olive oil to a paste.
Massage paste generously over the roast.Insert meat thermometer so you can read the temp through the oven door.
Put roast in oven and cook for 30 minutes. Turn oven off. DO NOT OPEN THE OVEN DOOR!
1 hour and 30 minutes before serving time, turn oven to 325 degrees F. DO NOT OPEN OVEN DOOR.
Starting from the time oven comes up to temperature, cook for 1 hour. Check thermometer and take out when it read beef rare.
Let rest 20-30 minutes. Remove most of the fat from roaster and add broth. Cook down about 1/2 and serve with roast.