How to Make It
Combine the garlic, green onions, soy sauce, vinegar, honey, ginger, oil, and red pepper flakes in a large zip-top plastic bag.
Slice the pork in half lengthwise, leaving a 1/2-inch thick hinge. Open the tenderloin as you would a book and cover with plastic wrap; pound with a meat mallet or heavy skillet to a 3/4-inch thickness. Add the pork to the plastic bag and turn to coat. Marinate at least 2 to 8 hours.
Preheat the broiler.
Remove the pork from the marinade and season with the salt. Place pork on a large baking sheet or broiler pan and broil 5-inches from the heat source, 3-4 minutes per side or until a thermometer inserted into the thickest portion registers 150°F. Transfer to a cutting board, cover loosely with foil and let stand 5 minutes before slicing.