In a bowl, whisk together the orange juice, lime juice, olive oil, garlic, orange zest, cumin, oregano, salt, pepper, and red pepper flakes. The result should be a bright, garlicky marinade that smells incredible — bold, zesty, and punchy.

Place your pork shoulder roast in a large zip-top bag or bowl and pour the marinade over the meat, turning to coat. Add the sliced onions to the mix. Seal the bag or cover the bowl and refrigerate for at least 8 hours, preferably overnight. This long marinade time is key to infusing the pork with flavor all the way through.

Slow Cooker (Crock Pot) Method:

Place the marinated pork and onions into your slow cooker. Pour any remaining marinade on top. Cook on low for 8 hours or until the pork shreds easily with a fork. This is one of the best pork roast crock pot recipes slow cooker fans can rely on — hands-off, full of flavor, and impossible to mess up.

Preheat your oven to 300°F. Heat a tablespoon of olive oil in a Dutch oven over medium-high heat. Sear the pork shoulder roast on all sides until browned (about 3–4 minutes per side). Add the onions and marinade to the pot, cover tightly with a lid or foil, and roast in the oven for 4 hours or until fork-tender.

Once cooked, transfer the pork to a large platter or cutting board. Shred with two forks, discarding any large pieces of fat. If you like crispy edges, spread the shredded pork on a baking sheet and broil for 5–8 minutes, just until the edges caramelize.

Drizzle with a few spoonfuls of the reserved cooking juices. You can serve the pork with rice, black beans, or pile it high into sandwiches with a tangy slaw.