How to Make It
Prepare the pork: Place tenderloins in a baking dish, and drizzle with oil. Sprinkle with salt and pepper. Use your hands to rub oil and seasonings all over meat, and set aside at room temperature.
Prepare a charcoal grill for two-zone cooking, and build a medium-high fire, or heat a gas grill to high. When the coals are glowing red and covered with a layer of fine gray ash, add a few chunks of oak to the fire, and carefully wipe the preheated grates with a lightly oiled paper towel. Using a grill brush, scrape the grill grates clean, then carefully wipe with a lightly oiled paper towel again. Place a grill basket over fire to preheat at least 5 minutes.
Prepare the tomatillo salsa: Combine tomatillos, onion, chiles and garlic in a bowl. Drizzle with oil, and toss to combine. Add vegetables to preheated grill basket. Grill, using tongs to flip and rotate vegetables and basket around heat as needed, until chiles and onions are blistered, about 5 minutes for chiles and 10 minutes for onions; garlic is blackened in spots and feels soft to the touch, about 5 minutes; and tomatillos are charred and their juices begin to bubble, about 10 minutes. Remove each item from heat as it finishes cooking, returning them to same bowl.
Grill the pork: Place pork over direct heat, close grill, and vent for smoking. Grill, using tongs to roll tenderloins every couple of minutes (be sure to close the grill each time to avoid flare-ups), until meat is deeply browned on all sides and cooked to medium (150°F), 10 to 12 minutes. Transfer meat to a cutting board; let rest 8 to 10 minutes.
Make the tomatillo salsa: While meat rests, stem chiles, and peel garlic. Combine chiles, garlic, tomatillos, onion, and salt in a food processor. Pulse until vegetables are coarsely chopped. Add cilantro, crema, and oregano, and puree until smooth. Taste salsa, and adjust seasonings as desired. Slice pork, and serve with salsa.