Season all sides of the pork shoulder with salt, cinnamon, and oregano.

Place quartered onions at the bottom of a slow cooker. Put the pork shoulder on top of the onion.

Pour in the pineapple juice and orange juice. Throw in the chipotles with the adobo sauce, bay leaf, and 3 smashed garlic cloves. Top the pork shoulder with the pineapple slices.

Cover the slow cooker and set on low speed for 8 hours or high speed for 4 hours. 8 hours will lend the most tender meat, but 4 hours will still be succulent.

Remove the pork shoulder and let rest for at least 10 minutes. Reserve the pineapple.

While the pork is resting, combine the coconut milk, last 2 cloves of garlic, and salt and pepper. In a small saucepan over medium high heat, simmer the coconut milk mixture for about 3 minutes or until it's reduced a bit. Set aside.

With two forks, shred the pork carnitas into a bowl, adding some of the juices from the slow cooker to keep it moist.

Serve the carnitas with lettuce wraps or warm tortillas and the reserved pineapple. A squeeze of lime and cilantro leaves is optional. Top with the coconut sauce.