Preheat your oven to 400°F (200°C).
In a medium bowl, combine the shredded chicken and BBQ sauce, mixing well to coat the chicken evenly.
On a large sheet pan, spread out the tortilla chips in an even layer.
Evenly distribute the BBQ chicken over the tortilla chips.
Sprinkle the black beans, corn, jalapeño slices (if using), and diced red onion over the chicken.
Top everything with shredded cheddar cheese.
Bake in the preheated oven for 10-15 minutes, or until the cheese is melted and bubbly.
Remove from the oven and let cool for a couple of minutes.
Drizzle sour cream over the nachos and garnish with fresh cilantro and diced avocado (if using).
Serve immediately and enjoy!