Step 1

Cut pork loin into 3 equal pieces.

Step 2

Turn a slow cooker to Low. Add orange juice, lime juice, lemon juice, and peppercorns, then add onion.

Step 3

Mix garlic, salt, and oregano into a paste and rub all over pork pieces. Place pork in the slow cooker.

Step 4

Cook on Low until pork is slightly pink in the center, 9 to 10 hours. An instant-read thermometer inserted into the center should read at least 145 degrees F (63 degrees C). Pull apart meat with 2 forks and let sit for 1 hour before serving.