Preheat Oven: Preheat your oven to 375°F (190°C).
Cook Ground Beef: In a skillet, cook the ground beef over medium-high heat until browned and fully cooked. Add the taco seasoning and stir until well combined.
Layer Nachos: In a large baking dish, arrange a layer of tortilla chips to cover the bottom. Spoon the cooked ground beef over the chips. Sprinkle the black beans evenly over the beef. Top with shredded cheddar cheese and jalapeño slices.
Bake Nachos: Bake in the preheated oven for 10-12 minutes or until the cheese is melted and bubbly.
Prepare Toppings: While the nachos are baking, mix the sour cream and lime juice together in a small bowl. Season with salt and pepper to taste.
Add Final Touches: Once the nachos are out of the oven, add the diced avocado on top.
Serve: Serve the loaded nachos hot with a dollop of sour cream mixture and guacamole.