Step 1

Preheat the oven to 375 degrees F. Coat a 2-3 quart baking dish with cooking spray.

Step 2

Heat the olive oil in a large pan over medium high heat. Add the beef and cook for 4-5 minutes or until just browned, breaking up the meat with a spatula.

Step 3

Add the onion and cook for an additional 3-4 minutes or until onion is translucent.

Step 4

Stir in the taco seasoning and red salsa. Simmer for 3-4 minutes.

Step 5

Remove the pan from the heat and stir in the sour cream.

Step 6

Lightly crush the Doritos. Spread 1/3 of the chips over the bottom of the prepared pan. Place 1/2 of the meat mixture on top of the chips, then add 1/3 of the cheese in an even layer.

Step 7

Repeat the process with another 1/3 of the chips, the rest of the meat, and 1/3 of the cheese.

Step 8

Add the remaining chips, then the final layer of cheese. Cover the baking dish with foil.

Step 9

Bake for 30 minutes. Uncover and bake for an additional 10-15 minutes or until cheese is melted and starting to brown.

Step 10

Sprinkle the tomatoes and green onions over the casserole, then serve. Top with additional taco flavorings such as sour cream, olives, etc. if desired.