In a small bowl, combine chili powder, cumin, oregano, salt and pepper. Season pork shoulder with spice mixture, rubbing in thoroughly on all sides.
Place garlic, onions, orange juice, lime juice and seasoned pork shoulder into a 6-qt slow cooker. Cover and cook on low heat for 8 hours or high for 4-5 hours.
Remove pork shoulder from the slow cooker and shred the meat before returning to the pot with the juices; season with salt and pepper, to taste, if needed. Cover and keep warm for an additional 30 minutes.
Preheat oven to broil. Place carnitas onto a baking sheet with some of the cooking fat and liquid, and broil until crisp and crusted, about 3-4 minutes.
Serve immediately.
Notes
Use the right size crockpot. A 6-qt slow cooker is ideal for this recipe. If the slow cooker is too small, the pork may not cook evenly. If the slow cooker is too large, the liquid may cook down too quickly, causing the pork to burn.
Avoid lean meats. Opt for pork shoulder or pork butt, avoiding lean meats such as pork tenderloin or pork chops (lean cuts tend to dry out).
Make it crispy. Broiling is essential for perfectly browned, crispy edges. Broil the shredded pork, about 6 inches from the broiler, in a single layer on a sheet pan with some of the leftover cooking juices until crispy and caramelized. Watch carefully as the pork can quickly burn under the broiler!
Make ahead of time, but skip the broil. When making ahead of time, shred the meat and store as needed, broiling just before serving.
Meal prep for the week. This recipe is ideal for big batch cooking! Repurpose the leftover pork throughout the busy weeknights for tacos, quesadillas, burrito bowls and salads.
Freeze for up to 3 months. Let the carnitas cool completely. Portion into plastic freezer bags in individual servings with some of the leftover cooking fat and liquid to prevent the meat from drying out. Label, date and freeze up to 3 months. To reheat, thaw overnight in the fridge, reheating in the oven or stovetop until crispy.