You can prep this ahead of time by making the meat in advance and then just pop it in the oven before you head out trick or treating for an instant fav!
2-1/2 pounds lean ground beef
1 envelope taco seasoning
1 can (8 ounces) tomato sauce
3/4 cup water
1 package (15-1/2 ounces) nacho-flavored tortilla chips, crushed
2 cups shredded Monterey Jack cheese
2 cups shredded cheddar cheese
4 cups torn iceberg lettuce
1 medium red onion, finely chopped
10 slices tomato, halved
1 cup (8 ounces) sour cream
10 pitted ripe olives, halved
Preheat oven to 325°. In a 6-qt. stockpot, cook and crumble beef over medium-high heat until no longer pink, 7-9 minutes. Stir in seasoning, tomato sauce and water; bring to a boil. Reduce heat; simmer, uncovered, 15 minutes, stirring occasionally.
Spread chips evenly in a greased 15x10x1-in. baking pan; sprinkle with Monterey Jack cheese. Top with beef mixture; sprinkle with cheddar cheese. Bake until bubbly, 25-30 minutes.
Cut into ten 5x3-in. portions. Top each with lettuce and onion. Add tomatoes, sour cream and olives to make eyeballs.