Cut the pork shoulder into large chunks (about 3"). Season with salt and pepper. Heat a large pan and add olive oil. Brown the pork in small batches.
Using a vegetable peeler, peel 4-5 strips of rind off the oranges and 3 strips off the lime. Juice the oranges and lime.
Place pork, citrus juices, peels and spices in the slow cooker with chicken broth and onion.
Cook on high for 4-5 hours or low for 8 hours until the pork is fork tender. Discard bay leaf.
Turn the oven on to broil. Pull the pork into large chunks and place in a single layer on a large pan. Spoon a little bit of juice on top. Broil 4-5 minutes or until crisp. Stir and add a ladle a little bit more broth. Broil an additional 5 minutes.
Serve in tortillas with your favorite toppings.
(Nutrition information provided is an estimate and will vary based on cooking methods and brands of ingredients used.)