I was at the market recently trying to think of something new to cook, and I realized I had never cooked a pork tenderloin.
The fire. On weeknights I'm always using a Weber Genesis B gas grill, which is adequate for skewers and chicken breasts, but not for steaks, because it does not get hot enough to really sear it without overcooking it. You need charcoal for a good hot fire, and on weekends I'll sometimes build a wood fire, which does get nice and hot and is just a lot of fun. When I first tried this I didn't think that a wood fire would actually add any smoke flavor, but it really does.
Meat prep. As far as I could tell, the loins had not been treated with a solution of any kind, so I brined them in a typical solution of 1/4C kosher salt to 1q of water, with a few tablespoons of sugar. I let these go overnight, which might have been a little long, but not really; they were nicely seasoned throughout. I also coated them with a dry rub I had kicking around in the cupboard.
Cooking. I seared them on the hot side until they were pretty browned all over:
And then moved them to the opposite side, away from the fire:
I closed the lid for a few minutes so that they would be surrounded by the smoke from the fire and have a chance to pick up a little more of its flavor. Since the fire is so hot, you should only do this for a few minutes, as it is better to let meat cook slower than faster. I pulled them when they where 145 degrees in the center, so that carry-over cooking would take them to 150.
Plated. The tenderloin was just as I expected: tender, juicy, and...unremarkable. There's just not much flavor in that meat. But, the family liked it, and I made do with A1, lime, and serrano chiles to help it out a little.