Preheat oven to 350 degrees F.
Cut each tortilla into 8 chip size pieces. Add the chips to a baking sheet in a single layer and spray with olive oil. Bake 7-9 minutes or until the chips are crispy.
While the chips bake brown the ground beef over medium heat. Drain the grease then add the taco seasoning and water. Cook for 3 minutes.
Add all of the tortilla chips to a baking sheet, they do not need to be in a single layer.
Top the chips with the seasoned beef, cheese and onion.
Bake 5-10 minutes, or until the cheese is melted. Add any additional toppings.