For the pork, preheat the oven to 325℉. Make the pork rub. Combine brown sugar, garlic powder, paprika, dry mustard, cumin, chili powder, salt, and pepper in a small bowl. Stir to combine. Rinse off the pork butt and pat dry with paper towels.
Preheat a large dutch oven or soup pot with a lid to medium-high heat. Add a drizzle of olive oil to the pot. Rub spice mixture all over pork butt. Sear for 3-4 min per side. Add beer and cover. Bake for 3 1/2 to 4 hours until pork is falling apart.
Once pork is finished cooking, remove from pot and let cool for 15 minutes or so. Shred pork with forks or your hands and add to a large bowl. Add barbeque sauce and stir to combine.
Preheat broiler to high and position oven rack in the upper third of the oven. Arrange tortilla chips on a large baking sheet. Top with pulled pork (you won't use all of it) and shredded cheese. Top with pickled jalapeños. Place under broiler for several minutes or until cheese is melted and bubbly. Top with scallions, red onion, tomatoes, chopped cilantro, and avocado. Enjoy!