Thirty minutes prior to cooking, allow the pork to come to room temperature
Preheat your oven to 325°
Season your pork shoulder generously with salt and black pepper
Place a large braiser or Dutch oven over medium to medium high heat and add a few tablespoons of neutral oil
Sear the seasoned pork shoulder on all sides until deeply golden brown
Place the quartered onions and garlic cloves around the seared pork shoulder
Add 1 tablespoon of cumin, 2 teaspoons of dried oregano, 1 cinnamon stick, 3 bay leaves, 1/2 cup of fresh orange juice, 1 tablespoon of fresh orange zest, 1/3 cup of fresh lime juice, 1 tablespoon of fresh lime zest and 15 ounces of Guinness
Cover the pot and braise in a 325° oven for 3 to 3 1/2 hours
Once very tender, shred the pork
If desired, spread the shredded pork over a baking sheet and broil until the pork has crispy edges
Serve warm with rice, over greens or in tortillas