Combine the finely diced tomato, onion, jalapeño, and chopped coriander leaves in a bowl, then stir in the lime juice and salt.

Let the salsa sit at room temperature so the flavors meld and the tomato releases its juices into the mixture.

Preheat the oven to 200°C (400°F) so it is fully hot before the nachos go in.

Spread the tortilla chips in a single, slightly overlapping layer across a large oven-safe baking tray.

Scatter the cooked black beans and corn kernels evenly over the tortilla chips so every chip gets some topping.

Sprinkle the shredded cheddar cheese generously and evenly over the entire tray of chips.

Bake the tray in the preheated oven until the cheese is fully melted, bubbling, and lightly golden at the edges.

While the nachos are still hot, dollop the sour cream and guacamole over the top in small spoonfuls.

Spoon the rested salsa evenly over the nachos and scatter any remaining sliced jalapeño and coriander leaves on top.

Serve the nachos right away while the chips are still crisp and the cheese is hot.