Place the pork tenderloin in a non-reactive shallow dish that’s just large enough to accommodate it, or in a large plastic resealable bag.
Put all the other ingredients in a small mixing bowl or glass measuring cup. Mix very well with a flat whisk until well combined.
Pour the marinade over the pork tenderloin, toss it around to make sure it’s completely coated, cover and place in the refrigerator to marinate overnight. If using a resealable bag, make sure to place it in a large plate or dish to catch any potential leaks.
Flip the pork tenderloin once or twice while it’s marinating to ensure even flavoring.
In a large heavy skillet set over medium-high heat, add a few tablespoons of heat stable healthy cooking fat such as ghee, lard or avocado oil. When the pan is nice and hot, remove the tenderloin from the marinade, let it drip for a few seconds and place it in the skillet. Sear the meat on all sides until a dark golden crust develops, about 2 to 3 minutes per side.
Remove any burnt bits from the pan and then add the marinade; reduce heat to medium-low and continue cooking the meat for about 20 to 25 minutes, turning the tenderloin every now and then to ensure even cooking / glazing, until there is no more liquid in the pan, save for the fat.
Transfer the meat to a plate and refrigerate uncovered until the next day.
Slice the meat on a diagonal as thinly as you can and arrange on a serving platter. Garnish with lettuce leaves and fresh herbs if desired.