Roast Pork Tenderloin (AKA "Dinosaur Tongue")

Once a month we usually roast a gigantic pork loin purchased from Costco. This one was 3.584kg when we started, and the reason I know that is because how long you cook it at a high heat is dependent on how much it weighs. We served this for a family dinner party a few months ago and my cousin, upon seeing it sitting on the cutting board, said (to the amusement of my boys) "What is that, a dinosaur tongue?"
I have been making pork loin exactly this same way every time since I discovered this recipe. There is NO going back. Gone are the days of tough, dry, less-than-tasty. Hello delicious.

Large pork loin - know the weight, in pounds (mine was 7.901lbs)
Spice Rub of your choice- I like: 1 tsp sea salt, 1 tsp black pepper, 1 tsp garlic powder, 1 tsp onion powder, 1/2 tsp dried thyme

Start by pre-heating your oven to 500*F. Get that roast in a large roasting pan, dry off any excess liquids- you don't want it dripping into the pan or there will be burning- then rub the spice blend all over. 
Put it into the oven (I use my bottom rack) just like this- no cover, no liquid in the pan. Cook at 5.5 minutes per pound exactly- set the timer- and here's the magical part: when that timer goes off, turn off your oven, and set the timer again for 45mins-1 hr.
Do NOT open your oven door.
When the timer goes off again, pull it out- check the internal temperature- it should be 145*. Let rest 10 mins. or so before slicing.
I promise, this works. It sounds scary to leave it in the oven and it goes against every instinct not to open that oven door, but trust the process.

Verdict: Every time, a unanimous "Mom, this is the best roast ever!" from both boys. Husband and I enjoy every bite.
And the leftovers = awesome meal starter. Thai pork wraps, pork and potato chowder, pork stir-fry, etc.