Rub the pork loin evenly with ground cumin, chili powder, garlic powder, sea salt, and black pepper.
Place the seasoned pork in a slow cooker and pour the orange juice around the base.
Cover and cook on low for 7 to 8 hours until the meat is tender and shreds easily with a fork.
Remove the pork from the slow cooker, shred it thoroughly, and discard any excess liquid.
Heat a non-stick skillet over medium-high heat and sear the shredded pork for 3 to 5 minutes until the edges are golden and crispy.
Warm the corn tortillas in a dry pan until they are soft and pliable.
Thinly slice the radishes and finely dice the red onion.
Assemble the tacos by filling the tortillas with the crispy pork and topping with radishes, onion, cilantro, and a fresh squeeze of lime juice.