Preheat smoker to 275 degrees Fahrenheit (135 degrees Celsius).
Season the pork shoulder with salt and pepper very liberally, making sure to cover all sides.
Place the pork shoulder in the smoker and let it cook until it reaches an internal temperature of 175 degrees Fahrenheit (80 degrees Celsius).
Once the pork shoulder reaches 175 degrees Fahrenheit, wrap it tightly in foil and place it back in the smoker.
Remove the pork shoulder from the smoker once it reaches an internal temperature of 203 degrees Fahrenheit (95 degrees Celsius).
Let the pork shoulder rest for at least 30 minutes before shredding it into small pieces.
While the pork is resting, prepare the pico de gallo. In a bowl, combine diced tomatoes, diced serrano pepper, diced sweet onion, chopped cilantro, lime juice, salt, and pepper. Mix well and set aside.
Warm up the cheese sauce in a saucepan over low heat.
To assemble the nachos, start by placing a layer of yellow round tortilla chips on a large plate.
Add a generous amount of shredded pork on top of the chips.
Pour the warm cheese sauce over the pork.
Add a few spoonfuls of the pico de gallo on top of the cheese.
Sprinkle some pickled jalapeños over the pico de gallo.
Finally, add a dollop of sour cream on top of the nachos.
Repeat the layering process until all the ingredients are used up.