Add mashed avocado, Worcestershire sauce, garlic powder, cumin, mayo and Sriracha to a medium bowl and mix to fully combine, add grated onion, and ground chicken. Combine until ingredients are fully incorporated. If you’ve got the time, let the mix sit in the fridge for at least 30 mins as it doesn’t contain eggs to bind it. The fridge time helps with that.
Meanwhile, make the Big Mac sauce.
Combine all ingredients in a small bowl, cover and refrigerate until ready to use. You can make this days ahead and keep refrigerated. It gets better over time. Stir before serving. Store in the fridge for up to 2 weeks. Makes about 3/4 cups.
When you’re ready to make your smash tacos, heat a griddle or pan to med, med-high. Spray griddle with oil.
Using an ice cream scooper, scoop meat mixture onto the center of the tortilla and ‘smash it”, meat side down onto the griddle and press down with a spatula to spread the meat thin and even. It won’t take long for the meat to be cooked through. Then using your spatula flip the taco over and add your cheese on top of the meat, allowing it to soften. When the tortilla has browned in spots, fold the tortilla in half and remove to your serving plate. Cover loosely with foil to keep them warm.
Once all of your smash tacos are done, It’s time to dress them! Add ketchup, mustard and onion, lettuce and Big Mac sauce. Tuck in some pickle slices here and there and enjoy!