You can easily make the pork ahead of time!
Heat a large skillet over medium-high heat and add the canola oil. Add the pork and sear on all sides until golden, about 2 minutes per side. Place the pork in the crockpot with the beer and add the salt, pepper and spices. Cook on low for 12 hours or high for 6 to 8 hours. Once finished, the pork should shred easily with a fork.
Before serving the pork, I like to crisp it up in the oven. To do this, I spread the shredded pork in a large baking dish. Preheat the oven to 400 degrees F. Place the baking dish in the oven and roast for 30 minutes, tossing the pork with a fork every 10 minutes. You don’t HAVE to do this step, but it really makes it taste like authentic carnitas.
Heat a cast iron skillet over medium-high heat and add the canola oil. Add the tortilla pieces in batches (however many your skillet can hold in a single layer) and fry until golden brown, about 2 to 3 minutes. Remove and place on a paper towel to drain excess grease. Sprinkle the chips with salt and repeat until your tortillas are gone.
To assemble the nachos, lay the chips in a layer on a large baking sheet (I like to cover mine with foil first). Sprinkle on the grated cheese then add on the pork. Drizzle on half of the queso. Place the nachos in the oven and cook until heated through and the cheese is melted. Remove the nachos and cover with the scallions, peppers, avocado, cilantro, mango, tomatoes and red onion. Drizzle more queso on to before serving!