Season the black beans with lime juice and salt to taste.
Arrange the tortilla chips in one layer on a serving platter or comal. For heavily loaded nachos, add a second layer of chips.
Scatter the beans over the chips. Top with pico de gallo, then drizzle with cheese sauce and chile de árbol salsa. Add guacamole, if desired.
Serve right away.
Notes
Prep time: This includes making the pico de gallo and assembling the nachos. The cheese sauce and chile de árbol salsa can be made ahead. Add time if making those from scratch or preparing guacamole.
Sheet Pan: For 6-8 servings, use a regular large baking sheet, two cans of beans, and enough chips for two layers. Layer half the chips with some toppings, then add the remaining chips and toppings. One batch each of pico, guacamole, salsa, and cheese sauce is enough for the larger pan. With the smaller platter, you’ll have extra toppings to serve alongside.
Make the pico fresh for serving. You can make the cheese sauce and chile de árbol salsa ahead, but prepare the pico right before assembling the nachos.
Spicy or mild salsa: I used 10 chiles in the chile de árbol salsa for this batch; my usual recipe calls for 20-30. Adjust to your preferred heat.