Roll out crescent rolls and place in a pie pan or 9x9 pan. Bake for 8 minutes at 350 degrees or until golden brown.
Prepare ground beef and taco mix using only 1/2 cup water. Spread ground beef mixture on bottom of pan. Layer with 1/2 of crushed Doritoes. Spread sour cream as next layer, then add rest of the chips. Top with cheese (and tomatoes and onions, if desired). Bake at 350 degrees for 20 minutes.