Preheat your smoker to 225°F.
Ina small bowl, mix the chili powder, smoked paprika, ground cumin, dried oregano, salt, and black pepper to make a rub.
Rub the spice mixture all over the pork shoulder.
Place the pork shoulder in the smoker and smoke for 3-4 hours, or until the internal temperature reaches 160°F.
Remove the pork shoulder from the smoker and transfer it to a large Dutch oven or heavy pot.
Add the chopped onion, minced garlic, and beer to the pot. The liquid should come up to about halfway up the side of the pork shoulder
Cover the pot with a lid and place it in the oven at 325°F for 3-4 hours, or until the pork is tender and falls apart easily.
Once the pork is done, remove it from the pot and shred it with two forks.
Strain the liquid from the pot and reserve it
Heat a skillet over medium-high heat and warm up the shredded pork in the skillet. Pour some of the reserved liquid over the pork and cook until the liquid has been absorbed.
Squeeze the juice of one lime over the pork
Serve the pork on warm corn tortillas with your favorite toppings, such as shredded cabbage, diced tomatoes, cilantro, lime wedges, avocado, and sour cream
Enjoy your delicious and flavorful beer braised smoked pork tacos!