Trim and cut the pork: Pat the pork shoulder dry and trim excess thick fat.
Cut into 3–4 large chunks for faster, more even cooking.
Mix the spice rub: In a small bowl, combine salt, pepper, smoked paprika, cumin, coriander, cinnamon, and red pepper flakes if using. Rub this all over the pork pieces.
Layer the slow cooker: Add the red onion slices and minced garlic to the bottom of the slow cooker. Pour in the pineapple with its juice, the chicken broth, soy sauce, and apple cider vinegar.
Add citrus: Zest the orange directly into the cooker.
Squeeze in the orange juice and the juice of one lime. Stir in brown sugar or honey to balance the acidity.
Nestle the pork: Place the seasoned pork pieces on top of the onion and pineapple mixture, turning once to coat.
Cook low and slow: Cover and cook on Low for 8–10 hours, or on High for 4–5 hours, until the pork is very tender and shreds easily with two forks.
Shred the meat: Transfer the pork to a large bowl and shred. Skim excess fat from the cooking liquid if needed.
Reduce and season the sauce: Taste the cooking liquid.
If it’s thin, pour a few cups into a saucepan and simmer 5–8 minutes to reduce slightly. Adjust with a pinch of salt or a squeeze of lime.
Combine: Return the shredded pork to the slow cooker and toss with enough sauce to coat. Keep warm for serving.
Serve: Top with chopped cilantro and extra lime.
Build tacos, sliders, or bowls with rice and crunchy slaw.