Step 1In a large bowl, combine the garlic, salt, oregano, cumin, black pepper, chili pepper, crumbled bay leaves and orange zest. Stir in the vinegar, orange and lime juices to make a coarse paste. Add the pork pieces and toss until the pieces are evenly coated with the spice paste. Set aside to marinate while you finish the other preparations.
Step 2Trim and cut the onions lengthwise into 1/4 -inch-thick slices. Arrange the slices in an even layer on the bottom of the slow cooker insert. Pour the broth over the onions. Arrange the pork in an even layer over the onions, pouring over any reserved marinade.
Step 3Cover the insert and place it in the slow cooker. Set the cooker to high heat and cook 4 to 4 1/2 hours until the pork is fork-tender. Remove from heat and crack the lid to allow the mixture to cool slightly. Gently stir the pork with the onions and serve.