Preheat your oven to 400°F (200°C). Line a baking sheet with parchment paper or foil.
- In a large bowl, toss the diced zucchini, bell pepper, red onion, and corn with olive oil, cumin, chili powder, salt, and pepper. Spread the vegetables evenly on the prepared baking sheet.
- Roast the vegetables in the preheated oven for about 15-20 minutes, or until they are tender and slightly caramelized, stirring halfway through.
- On a large oven-safe baking dish, layer the tortilla chips. Evenly distribute the roasted vegetables over the chips, followed by the black beans (if using). Sprinkle both cheddar and mozzarella cheeses over the top.
- Bake the nachos in the oven for 8-10 minutes, or until the cheese is melted and bubbly.
- Remove the nachos from the oven and garnish with fresh cilantro, guacamole, sour cream, jalapeño slices (if using), and a squeeze of lime juice. Drizzle with hot sauce for an extra kick, if desired.
- Serve immediately while still warm, and enjoy!