Rub the pork shoulder with ground cumin, dried oregano, sea salt, and black pepper.
Place the seasoned pork in a slow cooker along with the minced garlic, orange juice, and half of the lime juice.
Cover and cook on low for 7 to 8 hours until the meat is tender and easily shredded with a fork.
Remove the pork from the slow cooker and shred the meat using two forks, discarding any excess fat.
Heat the avocado oil in a large skillet over medium-high heat.
Add the shredded pork to the skillet and press down with a spatula, searing for 3 to 4 minutes until the edges are golden and crispy.
Warm the corn tortillas in a dry pan or over an open flame until they are soft and pliable.
Assemble the tacos by dividing the crispy pork between the tortillas and topping with diced white onion, sliced radishes, and fresh cilantro.
Finish with a squeeze of the remaining lime juice and serve immediately.