Preheat the oven to 350°F. Line a baking sheet with parchment paper. In a saucepan, add the mozzarella cheese and cook over medium-low heat and stir for 3 to 4 minutes, or until melted. Transfer the cheese to a bowl. Add the almond flour and sea salt, and knead the dough until it is smooth. On a flat surface, between 2 sheets of parchment paper, roll the dough to ¼-inch thick. Cut the dough into triangle chip shapes. Transfer the dough pieces to the prepared baking sheet and bake for 10 to 12 minutes, or until lightly browned and crisp. Remove from the oven and let cool.
Make the toppings:
In a skillet, heat the olive oil over medium-high. Add the onion and cook until soft. Add the beef, and cook until it is browned and no longer pink. Add the tomato paste and cook for 5 minutes. Add the cayenne pepper, sea salt, and black pepper, and stir to combine.
In a small bowl, add the smashed avocado and lime juice, sea salt, and black pepper and stir well to combine.
To serve:
Preheat the oven to 350°F. In an ovenproof skillet or on the baking sheet, place a layer of tortilla chips. Top the chips with a layer of the beef mixture. Sprinkle the cheddar cheese over the beef. Repeat the layers in the same order. Heat the nachos in the oven for about 3 minutes, or until the cheese is melted. Serve topped with the Pico de Gallo, avocado, black olives, and sour cream. Top with the cilantro. Serve immediately.