1. Preheat oven to 350°F.
2. Place cauliflower and walnuts into the Food Processor Work Bowl fitted with the Multi-Use blade. Secure the lid. Pulse 6-8 times. Stop, remove the lid, and scrape down the sides of the Work Bowl. Secure the lid and pulse an additional 6-8 times or until the mixture is roughly chopped into small pieces. Remove mixture and place in a large bowl.
3. Place the remaining ingredients (except for serving) into the Vitamix container and secure the lid. Start the blender on its lowest speed, then quickly increase to its highest speed. Blend for 35-45 seconds.
4. Add the adobo sauce to the chopped cauliflower and walnut mixture, tossing gently to combine. Spread mixture out evenly onto a 1/2 sheet tray sprayed with non-stick spray. Bake in preheated oven for 15-20 minutes, then remove and turn mixture with a spatula. Return mixture to oven and cook an additional 15-20 minutes.
5. Remove mixture from oven and assemble each corn tortilla with a small helping, topped with shredded cabbage, diced tomatoes, and onions.