Cut cauliflower head into florets and add to a large mixing bowl. Add olive oil and taco seasoning then stir till all florets are coated. Line an air-fryer or baking sheet with parchment paper then cook in oven or air-fryer 425F for 20-25mins flipping halfway. Keep a close eye to make sure they don't burn.
While cauliflower is roasting, place all ingredients for the avocado crema besides the water into a blender. Add water until you reach your desired sauce consistency - it should be smooth and creamy. Taste as you go to see where seasoning needs adjusting.
Warm tortillas over an open flame on the stove then place on serving plates. Top tortillas with shredded cabbage and roasted cauliflower then drizzle over avocado crema. Serve with chopped cilantro and additional lime wedges.