Rub the pork shoulder evenly with sea salt, black pepper, ground cumin, and dried oregano.
Place the seasoned pork in a slow cooker along with the minced garlic and fresh orange juice.
Cover and cook on low for 8 hours until the meat is tender and easily pulls apart with a fork.
Remove the pork from the slow cooker and shred it using two forks, discarding any large pieces of fat.
Heat a large non-stick skillet over medium-high heat and add the shredded pork in a single layer.
Sear the pork for 3-5 minutes without stirring until the bottom is golden and crispy, then flip and sear briefly.
Warm the corn tortillas in a dry skillet for 30 seconds per side until soft and pliable.
Fill each tortilla with the crispy pork and top with diced red onion, chopped cilantro, and thinly sliced radishes.
Serve immediately with fresh lime wedges to squeeze over the top.