Ribeye or NY strip... rare. That means not moving on the plate.

I'm weird in that I don't like filets, but I love whole beef tenderloin. Yes, it has been explained to me that it is the same thing, but my way of cooking it tastes different than a filet in a restaurant.
I have been cooking whole tenderloins for 20+ years the same way... and nobody has ever complained. Well, that's not exactly true, a few wanted it more well done... that's what a microwave is for.

As much as I love to cater to my guests, I will not ruin a whole tenderloin for the tastes of 1 or 2 guests.
My way... for a 4-7+lb whole beef tenderloin
1. Preheat oven to 500 (bake not broil).
2. In heavy roasting pan ( I have a Calphalon with handles) spray it heavily with Olive Oil Pam. Cover with thin sliced sweet onion.
3. Lay trimmed up tenderloin on top of onions. Cover (heavy) with restaurant (coarse) black pepper and garlic powder.
4. Put in oven for 20 minutes. (Keep an eye on it - it will smoke a bit, not good to set off smoke alarm)
5. At 20 minutes, pull out of oven, reduce temp to 325.
6. Pour beef broth into pan - not over the meat so that it comes about half way up on meat (I use Swanson's in the box - usually takes most of 2 containers)
7. Stick a meat thermometer into the thickest part.
8. Put back in oven, set timer for 15 minutes. Start checking thermometer.
9. When thermometer barely hits rare, take it out!
10. Let rest in pan about 5 minutes.
11. Take out of pan, put on a cookie sheet with sides and let rest at least another 5 minutes.
Carefully slice on cookie sheet, as it keeps the juices from running all over counter ( I have learned this the hard way!!)
The small end turns out just medium, the thickest part is pretty rare. Makes everyone happy,happy, happy!

I make a sour cream horseradish sauce and bernaise sauce to go with. And I always serve it with mushrooms sauteed in butter, garlic, salt & pepper.
The onion/broth can be turned into excellent gravy. I usually save it, and make it into gravy a day or two later. I always make this for Christmas Eve, and I don't have time to mess with the gravy then. It depends on how much I have left over as to whether or not it's worth the effort to make gravy. It could be frozen and saved though.