Preheat the oven. Set your oven to 400°F (200°C). Line a large sheet pan with foil or parchment for easy cleanup.
Lightly spray or oil the surface to help keep chips crisp.
Prep the chicken. In a bowl, toss the cooked chicken with enough BBQ sauce to coat generously. If your chicken is plain, season it with a pinch of salt, pepper, and a little chili powder or paprika for extra depth.
Build the first layer. Spread a solid layer of tortilla chips on the sheet pan. Aim for a single layer with some overlap so toppings reach most chips.
Add the cheese and chicken. Sprinkle half of the shredded cheese over the chips.
Distribute the BBQ chicken evenly across the pan so every handful gets some.
Layer the beans and corn. Scatter black beans and corn over the chicken. These add texture, protein, and a bit of sweetness.
Top with more cheese. Add the rest of the shredded cheese. A second layer helps glue everything together and gives that melty, stretchy finish.
Bake until melty. Pop the pan in the oven for 8–10 minutes, until the cheese is fully melted and the edges of a few chips just start to toast.
If you like a bit of char, switch to broil for the last 1–2 minutes, watching closely.
Add fresh toppings. Remove from the oven and immediately top with red onion, jalapeño, tomatoes or pico, cilantro, and green onions. Dollop sour cream or Greek yogurt and add avocado or guacamole in small scoops.
Finish with a drizzle. Drizzle a little extra BBQ sauce over the top for shine and flavor. Serve with lime wedges for a bright squeeze right before eating.
Serve hot. Bring the sheet pan straight to the table with plates and napkins.
Nachos are best enjoyed immediately while the chips are still crisp.