Combine all of the ingredients for the DRESSING (except oil) in a food processor. While the processor is running, drizzle in the oil. Refrigerate until ready to use.
Cook the vegan "beefy" crumbles of your choosing and add 2/3 cup of water and a packet of taco seasoning (or to taste if using a homemade version).
Crush some of the Doritos on a serving platter and top with the "beefy" crumbles, corn, beans, tomatoes and vegan cheese.
Top with, lettuce, more of the crushed Doritos and garnish with vegan sour cream, avocados and chopped scallions. Serve immediately!