Cook ground beef over medium high heat in a large skillet. Crumble meat with a wooden spoon or spatula and cook until meat is browned. Then stir in taco seasoning and ½ cup water. Simmer until water is absorbed. Remove from the heat.
Mix sour cream with ranch mix. Chill until ready to serve.
Chop lettuce and place in a large serving bowl.
Top with meat, beans, tomatoes, olives, avocado, and cheese.
Next sprinkle with crushed Doritos and then dollop on ranch sour cream.