Preheat oven to 375°F (190°C).
Cook ground beef in a skillet over medium heat until browned.
Drain excess fat and stir in taco seasoning and water.
Simmer for 5 minutes until thickened.
Spread tortilla chips evenly on a large baking sheet.
Spoon seasoned beef evenly over chips.
Sprinkle black beans and corn over the beef.
Top generously with cheddar and Monterey Jack cheese.
Bake for 10–12 minutes until cheese is melted and bubbly.
Remove from oven and add diced tomatoes, jalapeños, olives, and cilantro.
Serve immediately with sour cream and guacamole on top or on the side.