Preheat oven to 400 degrees F. Lightly oil a baking sheet or coat with nonstick spray.
Heat olive oil in a large cast iron skillet over medium high heat. Add ground beef and garlic, and cook until beef has browned, about 3-5 minutes, making sure to crumble the beef as it cooks; stir in taco seasoning. Drain excess fat.
Place tortilla chips in a single layer onto the prepared baking sheet.
Top with ground beef mixture, black beans, corn and cheeses.
Place into oven and bake until heated through and the cheeses have melted, about 5-6 minutes.
Serve immediately, topped with tomato, onion, jalapeno, sour cream and cilantro.
Notes
Use a good quality sheet pan. A durable sheet pan is ideal – it will last for years with minimal wear and tear, and will help achieve even cooking and avoid warping at high temperatures.
Use thick, sturdy tortilla chips. Thick tortilla chips will prevent sogginess, support heavy loads without snapping or breaking, and withstand oven heat very well.
Drain the excess grease. Drain any excess grease and fat after crumbling the ground beef to prevent soggy chips.
Freshly grated cheese goes a long way. Pre-packaged shredded cheese contains anti-caking agents that can hinder its ability to melt properly.
Bake just before serving. Prep the meat, cheese, and toppings 24 hours in advance, baking just before serving for maximum freshness and crispiness.
Add cold toppings last. Always add cold, fresh toppings after the nachos have been baked.