Preheat oven to 375°F (190°C) and grease a 9x13 baking dish.
Cook ground beef in a skillet until browned.
Add onion and garlic; cook until softened. Drain excess fat.
Stir in taco seasoning and water. Simmer 3–5 minutes.
Mix in black beans, corn, and salsa. Cook 2 minutes.
Spread half the crushed tortilla chips in the baking dish.
Add half the beef mixture on top.
Sprinkle half the cheese over the beef.
Repeat layers with remaining chips, beef, and cheese.
Bake for 20–25 minutes until hot and bubbly.
Let rest 5 minutes before serving.
Add desired toppings and serve warm.