01 - Preheat the oven to 400°F.
02 - Heat olive oil in a skillet over medium heat. Add chopped onion and garlic; sauté until softened, about 2 minutes.
03 - Add ground beef to the skillet and cook, breaking it apart, until browned, 5 to 6 minutes.
04 - Stir in cumin, smoked paprika, chili powder, salt, black pepper, and tomato paste. Cook for 1 to 2 minutes, then remove from heat.
05 - Spread tortilla chips evenly on a large baking tray or ovenproof dish.
06 - Distribute the seasoned beef mixture evenly over the chips.
07 - Sprinkle shredded cheddar and Monterey Jack cheeses over the beef and chips. Add diced tomato, jalapeño slices, and black olives if desired.
08 - Bake in the preheated oven until the cheese is melted and bubbly, approximately 8 to 10 minutes.
09 - Meanwhile, mash the avocados with lime juice in a bowl. Fold in diced tomato, red onion, cilantro, salt, and black pepper until combined.
10 - Remove nachos from the oven, sprinkle with chopped cilantro, and serve immediately with guacamole on the side or atop.