This is one of our favorite easy weeknight meals. It's so good, and I always look forward to making this again. And each time I try other changes, like adding some minced garlic or perhaps a diced jalapeno pepper or chopped bell pepper or adding difference vegetables. There are just so many ways to change this easy but delicious Mexican casserole.
Preheat oven to 350°F (175°C). Spray a 9x13 baking dish with nonstick cooking spray; set aside.
In a large skillet over medium-high heat, cook ground beef until no longer pink. Stir in salsa, reduce heat, and simmer 20 minutes, or until liquid is absorbed. Stir in beans and corn, and cook just until heated through.
Spread crushed tortilla chips in bottom of prepared baking dish, and then spoon beef mixture over chips. Spread sour cream over the beef layer, and then sprinkle olives, green onion, and tomato over the sour cream layer.
Bake in preheated 350° oven for 25 to 30 minutes. Top with cheddar cheese and return to oven to bake another 5 minutes or just until the cheese starts to melt.