Begin by preparing the pork shoulder. Trim any excess fat and cut the meat into 2-inch chunks.
In a small bowl, mix together the salt, black pepper, ground cumin, dried oregano, chili powder, garlic powder, onion powder, and ground cinnamon to create the spice rub.
Thoroughly coat the pork chunks with the spice rub, ensuring each piece is well-seasoned.
Place the seasoned pork into the slow cooker.
Pour the chicken broth over the pork. Add the minced garlic, orange juice and zest, and lime juice to the slow cooker.
Cover and cook on low for 8 hours, or until the pork is tender and shreds easily with a fork.
Once cooked, transfer the pork to a bowl and shred it using two forks.
Preheat a skillet over medium-high heat. Add the shredded pork and cook for a few minutes until the edges are crispy.
To assemble the tacos, take a lettuce leaf and add a scoop of the crispy carnitas.
Top the carnitas with slices of avocado, a spoonful of pico de gallo, a sprinkle of cheddar cheese, and chopped cilantro.
Serve immediately and enjoy your keto-friendly Slow Cooker Carnitas Tacos!