Like the restaurant favorite, these fajitas will satisfy your Tex-Mex craving and be on the table faster than you can get takeout.
Combine chipotle chile and sauce, garlic, orange juice, lime juice, vinegar, oregano, cumin, salt and pepper in a blender or mini food processor; blend or process until the chipotle is chopped and the mixture is relatively smooth. Pour into a sealable plastic bag, add pork and seal, squeezing out any excess air from the bag. Turn to coat with the marinade. Refrigerate at least 1 hour and up to 8 hours.
Preheat grill to high or heat a large indoor grill pan over high heat. Remove the pork from the marinade (discard marinade). Grill the pork, turning occasionally, until an instant-read thermometer inserted diagonally into the center of the meat registers 145°F, 12 to 15 minutes. Transfer the pork to a cutting board and let rest for 5 minutes before slicing.
Lightly brush bell peppers and onion with oil. Grill until lightly browned and soft, turning once, 3 to 7 minutes. (If using a grill pan, you may need to grill the vegetables in two batches.) Let cool on a cutting board.
Thinly slice the pork and chop the onion. Toss the onion, peppers and pork together in a large bowl. Serve the fajita filling in tortillas with sour cream and salsa.
Chipotle chiles in adobo sauce are smoked jalapenos packed in a flavorful sauce. Look for the small cans with the Mexican foods in large supermarkets. Once opened, they’ll keep up to 2 weeks in the refrigerator or 6 months in the freezer. One pork tenderloin typically weighs about 1 pound, enough for 4 servings. You can marinate a whole pound in the same amount of marinade used to marinate the 8 ounces in this recipe and have enough cooked tenderloin for 2 dinners (for 2 people). Or freeze half for up to 3 months. To warm tortillas, wrap in foil and bake at 300°F until steaming, about 5 minutes. Or wrap in barely damp paper towels and microwave on High for 30 to 45 seconds.