whisk the marinade together.
add thinly sliced pork tenderloin and stir to coat. marinate at least 4 hours, ideally overnight
sear pork slices over high heat in a cast-iron skillet until charred
flip and cook until second side is charred.
add marinade to empty skillet and cook until thickened. add pork back to skillet and stir to coat.
toss with scallions + sliced serrano chile