Preheat cast iron skillet to medium-high heat.
Pour avocado oil into skillet, coating bottom.
Rinse room-temperature pork under cool water. Pat dry.
Generously coat with salt and pepper; massage both into pork with your hands.
When cast iron is completely heated (slightly smoking), sear pork on all four sides. (About 1 min. on each side.)
Transfer pork to slow cooker.
Cover with Trader Joe's Umami Seasoning, mustard, barbeque sauce, extra virgin olive oil, and raw coconut vinegar.
Cook on low for 8 hours.