Trim excess fat from the pork shoulder and cut into 2-inch chunks.
In a small bowl, combine the chili powder, cumin, garlic powder, onion powder, sea salt, and black pepper.
Rub the spice mixture evenly over the pork pieces.
Place the pork in a slow cooker or pressure cooker with the lime juice and orange juice, cooking until the meat is tender and easily shreds with a fork.
Once cooked, shred the pork using two forks and discard any remaining large pieces of fat.
Heat a non-stick skillet over medium-high heat and add the shredded pork, pressing down with a spatula to create crispy, golden-brown edges.
While the pork crisps, thinly slice the radishes and chop the fresh cilantro.
Warm the corn tortillas in a dry pan or over an open flame until pliable.
Divide the crispy pork between the two tortillas and top with sliced avocado, radishes, and cilantro.