I think if you follow the rules for rare beef, you will have the greatest luck in the world with it. When you buy a rib roast, calculate that one rib will serve 2 persons, so for six, you will need a 3 rib roast.

The timetable for roasting by this method is approximately 15 minutes per rib, or 5 minutes per pound of trimmed, ready to cook meat.  For example, a 3 rib roast, weighing 8 to 9 pounds, will roast for 40 to 45 minutes.

Bring the roast to room temperature.  Preheat the oven to 500 degrees.  Place the roast in a shallow roasting pan.  Sprinkle with a little flour and rub the flour into the fat; this will help seal the juices.  Season generously with salt and coarsely cracked black pepper.  To protect your oven from spattering fat; place a tent of aluminum foil loosely over the top of the meat.  Roast according to the above timetable, following the minutes exactly.  If you have a timer, set it to remind you.

       When the cooking time ends, turn off the oven heat, but do not open the oven door.  Allow the roast to remain in the oven for at least 1 hour or until the oven is lukewarm, about 2 hours.

The roast will be beautifully rare inside and retain a crunchy outside and an internal heat suitable for serving for as long as 4 hours.