either jerk marinade or greek marinade then charcoal grill on combination of direct and indirect heat.
i used to slow cook lean loins and they kept turning out sooooo dry, even when braised in liquids -- turns out it's because they're so lean they're best cooked quickly at higher heat. i like taking a loin and cutting it into chunks, then marinating and grilling. (i use walkerswood jamaican jerk paste, but may be too spicy for some)
one of my latest quick meals is to marinate the thin bone-in loin chops in OO, balsamic and various seasonings then quickly broil. way better/easier than pan frying!
If it's lean and most are then I would oven braise, liquid of your choice a little pink wont kill you I cook high heat till brown then lower and slow cook. I recently made one adding near the end a product I bought at of all place's Wal-mart that had black beans ,corn ,chipolte ,vinegar and no additives.Again just watch that it dont get to cooked let it rest also