Preheat the oven to 375°F. Brown the ground beef in a skillet over medium-high heat, breaking it into crumbles. Drain excess grease (optional), then stir in the taco seasoning and minced garlic. Simmer for 2 minutes.
Spread 1/2 of the tortilla chips in a single, slightly overlapping layer on a large rimmed parchment lined baking sheet.Spread 1/2 of the seasoned beef and black beans over the chips, then generously cover with both cheeses. Repeat with another layer of chips, beef, beans and cheese. Bake for 7-10 minutes, until the cheese is melted and bubbly. Keep an eye on the chips so the edges don't burn.
Sprinkle with diced tomatoes, black olives, and cilantro. Add dollops of sour cream, salsa, and avocado just before serving.