Peel and finely dice the yellow onion. Heat a large skillet over medium-high heat and add 1 tablespoon olive oil. Add the diced onion and cook, stirring occasionally, until softened and translucent, about 3–4 minutes.

Brown the beef

Add the ground beef to the skillet with the onion. Break it up with a spatula and cook until mostly browned and no longer pink, about 5–6 minutes.

Season and simmer

Stir in the minced garlic, chili powder, cumin, smoked paprika, kosher salt, and black pepper. Cook 30 seconds until fragrant. Add the tomato paste and 1/4 cup water, stirring to combine. Reduce heat to medium-low and simmer until thickened, about 3–4 minutes. Taste and adjust seasoning. Remove from heat and set aside.

Tortilla base & assembly

Preheat the oven to 375°F (190°C). Arrange half of the tortilla chips in an even layer on a large rimmed baking sheet or in a large ovenproof serving dish. Sprinkle half of both shredded cheeses evenly over the chips.

Evenly distribute half of the cooked taco meat over the cheese layer. Add another even layer of the remaining tortilla chips, then top with the remaining taco meat and remaining cheeses so cheese and meat are layered between chips and on top.

Bake & melt

Place the assembled nachos in the preheated oven and bake until cheese is fully melted and bubbling, about 6–9 minutes. For extra browning, switch to broil for 1 minute—watch carefully to avoid burning.

Fresh toppings & finish

While the nachos bake, dice the roma tomatoes, mince or finely dice the red onion, thinly slice the jalapeño or bell pepper, slice the black olives, and chop the cilantro.

When the nachos come out of the oven, immediately scatter the diced tomatoes, red onion, sliced peppers, black olives, and cilantro over the hot cheese. Serve with lime wedges on the side.

Offer the salsa on the side in a small bowl. Add optional sour cream and guacamole either dolloped on top or served alongside for guests to add as desired.