I can tall you all sorts of times to cook the thing, but it all boils down to checking the thermometers.
If you like it rare, cook it to 150 degrees in the thick part, remove from the oven, cover with foil and let it sit for 30 minutes.
If it's "just about raw" you can always put it back on the grill and cook it more....if it's over done, it's ruined.
And an $80 piece of meat is a lot to ruin!
Linda C

OOH Linda, 150°F is well done in my book. If you want it rare I'd take it out of the oven at 120°F or no more than 125°F at the most. Resting for 20 minutes will bring it up to about 130°F give or take a few degrees. Anything over 135 is over cooked especially for a beef tenderloin.

I usually do mine on the grill. But Barbara Kakfa's high heat oven method is fool proof.

Roasted Whole beef Fillet (Barbara Kafka)

According to Barbara........"I buy the meat by the inch. It cooks exactly the same way no matter the length as long as it s more than 4 inches long. When ordering, I usually allow about an inch and a quarter per person and an extra half inch for the two end slices. By this rule, six people will require an eight inch piece of fillet. The muscles in a fillet all run lengthwise so that when it is sliced across the serving it is also tenderized.

The fillet is also called the tenderloin, and it is tender. It is a long round muscle that hides behind the bones on which the shell steak and the rib roast reside. T-bone steaks have some of the shell and, on the other side of the bone, a circle of the fillet, or tenderloin. A filet mignon is a slice cut across the whole fillet to make an individual steak.

4 to 5 pound whole beef fillet (about 3 to 3 1/2 inches in diameter, a good 18 inches long)
1 tablespoon unsalted butter at room temperature
1 tablespoon olive oil
2 teaspoons kosher salt
1/4 teaspoon freshly ground black pepper
3/4 cup red wine for deglazing, optional, or 1 recipe semi-perigourdine sauce

Place oven rack on second level from bottom. heat oven to 500°F

Place fillet in an 18 x 12 x 2 inch roasting pan. Rub fillet with butter and oil. Sprinkle evenly with salt and pepper. roast for 10 minutes. turn. roast 10 minutes more. Transfer fillet to a serving platter. Pour or spoon off excess fat. Put pan on top of the burner. Add the wine or sauce and bring contents to a boil while scraping the bottom of the pan with a wooden spoon. Let reduce by half. Season with salt and pepper.

Ann, I was taking into account the fact that she thought The Barefoot Contessa's recipe was just about raw...

Totally agree, Ann. I take it off the grill or out of the oven at exactly 120 degrees F. After it sits for 20 minutes or so, it's perfectly medium-rare. Frankly, if you want to cook it to 'medium-well', you need to choose another (much less-expensive) cut of beef.

On the grill, I do the bare minimum of seasonings. If cooking in the oven, I puree a couple of garlic cloves with a softened stick of butter and a lot of McCormick's Spicy Grill-Mates seasoning, then rub it all over the meat. Makes a fab au jus.

What really sends it over the top is a superb horseradish sauce. Try this one.

1-1/2 c. mayo
2 T. Dijon mustard
2-1/2 T. whole-grain mustard
1/2 c. sour cream
horseradish, to taste
kosher salt, to taste
freshly-ground black pepper, to taste

Just keep adding horseradish until it's wonderful. Then cover and refrigerate. Tomorrow it will be even better!

sm

I've made this several times and the beef is fabulous. I use thermometers so I can't testify to the cooking times but I think the dry brining really makes a big difference.

Here is a link that might be useful: Tenderloin recipe

If you cook it to 150 degrees F in the thick part, the thinner sections are going to be TOAST.

My suggestion?

Break the tenderloin down into pieces of similar diameters.

That way you can pull the smaller diameter ones as they finish cooking.

And you must use a thermometer.

Stupid question of the day--

Do you wash the salt off? Does it disappear into the meat? Does the meat get salty?

Obviously I've never done anything like that.

Thanks in advance.

I like mine a little less than medium, still quite pink but not reddish. I cook to 130 and then let rest 15 minutes, the result is perfect for us. Definitely not rare but not overcooked either.

You can't do this without an instant read thermometer. It's well worth the $15 given the cost of the meat, an invaluable tool.

Also forget the thin end, thick end part. Either get an even centre cut from the butcher or fold the skinny end under itself and tie with butcher cord. The result should be an evenly sized piece of beef.

Now that I think of it, do you have a full beef tenderloin , untrimmed or is it trimmed? Does it have a membrane and two "sections"? Here is a video of someone trimming a full tenderloin for cooking. From the pictures can you tell which you have?

Most of what we are saying here applies to a trimmed tenderloin. When I talk about tying the thin end under I am referring to Step 6 of this video.

Here is a link that might be useful: Preparing a beef tenderloin

She said she wants Med-Medium Rare..agree with Sharon..cook to 130F and tent. I like it like Ann and pull off at 120F.
I also agree with Mike..I'd split it up..that way you can under or over cook pieces.
Specially since it's for rolls.

Happygram, no you don't wash the salt off..you don't coat it so much that there is a "skin" of salt, just a good rub or it. And the meat is perfectly seasoned. Not salty.

I've copied and pasted all of the information you've given me and watched the video as well. Of course, according to the video, I needed a special kind of knife which I loved adding to my knife collection. (I use the same 2 knives for everything but just love to collect them.)

Anyway, thank you all very much for your help. It's most appreciated.

Happygram (Mary)