Step 1

Coat the insert of a 4-quart or larger slow cooker with cooking spray. Smash 8 peeled garlic cloves. Thickly slice 1/2 medium Spanish or yellow onion. Place 1 tablespoon dried oregano, 1 1/2 teaspoons kosher salt, 1 teaspoon ground cumin, and 1/2 teaspoon black pepper in a small bowl and stir to combine.

Step 2

Pat 4 to 6 pounds pork shoulder dry with paper towels. Trim off any excess surface fat if desired; make sure it will fit in the slow cooker or cut it into two pieces to fit. Use a paring knife to cut 8 large slits into the pork 1 to 2 inches deep. Stuff a garlic clove into each slit.

Step 3

Place the pork in the slow cooker insert. Slowly pour 1 1/2 cups sour orange juice over the pork, making sure some of it gets into the slits. Use your hands to rub some of the juice into the pork, including the sides and bottom. Sprinkle all over with the spice mixture and use your hands to rub the seasoning all over the pork until well-coated.

Step 4

Top the pork with the onion. Cover and refrigerate at least 8 hours or up to overnight, flipping the pork once.

Step 5

Place the slow cooker insert in the slow cooker. Cook on the LOW setting until the pork is fork tender, about 8 hours.

Step 6

Arrange a rack in the middle of the oven and heat the oven to broil. Coat a rimmed baking sheet with cooking spray.

Step 7

Turn off the slow cooker and uncover. Spoon some of the cooking liquid over the pork. Transfer the pork to the baking sheet and let it rest for about 5 to 10 minutes (add the onions if desired or save for topping the pork later).

Step 8

Use 2 forks to roughly tear the pork into large chunks; do not shred the pork. Spoon a few tablespoons of the cooking liquid over the pork.

Step 9

Broil until the top of the pork is browned in spots and crisp, 5 to 10 minutes. Transfer the pork to a serving platter. Serve with cooked white rice, Cuban-style black beans, lime wedges, and fried plantains if desired.