Preheat and prep: Heat the oven to 400°F (200°C). Line a large sheet pan with parchment for easier cleanup.
Cook the beef: Heat a skillet over medium-high and add a drizzle of oil. Add the ground beef, breaking it up with a spatula, and cook until browned with no pink left, about 5–7 minutes.
Drain excess fat if needed.
Season it: Sprinkle in the taco seasoning and add the water. Stir and simmer 1–2 minutes until thickened and well coated. Taste and adjust salt if needed.
Remove from heat.
Prep toppings: Rinse and drain black beans. Chop onion, tomato, and cilantro. Slice jalapeños.
Dice avocado just before using to keep it fresh.
Build the base: Spread half the chips on the sheet pan in an even layer. Top with half the cheese, half the beef, and half the beans and corn. Keep everything fairly even so cheese touches most chips.
Second layer: Add another layer with the remaining chips, cheese, beef, beans, and corn.
Lightly sprinkle some red onion and jalapeño slices over the top (save some for fresh garnish after baking).
Bake: Place in the oven for 8–10 minutes until the cheese is fully melted and the edges of the chips are just starting to toast. Don’t walk away—nachos can go from perfect to too dark quickly.
Finish with fresh toppings: Remove from the oven and immediately add diced tomato, remaining onion and jalapeños, avocado (or dollops of guacamole), and cilantro. Add spoonfuls of sour cream and a few squeezes of lime juice.
Serve hot: Bring the whole pan to the table.
Offer hot sauce, salsa, or a queso drizzle on the side. Enjoy right away for the best crunch.