In a small bowl, combine the chili powder, cayenne pepper, garlic powder, black pepper, sea salt, cinnamon and allspice. Rub the mixture on your steak, on both sides. Preheat your grill to medium, and grill the steaks 5 minutes on each sides (for medium rare). Remove from the grill and set aside to rest for 10-15 minutes.
Meanwhile prepare your salsa. Combine the avocado, cucumber, red onion, cilantro, salt, jalapeño, habanero and serrano in a small bowl. Mix together and season with more salt to taste if needed. Set aside.
Slice your steaks thinly and prepare your tacos. Assemble the tacos by placing a handfull of cabbage on each taco. Top with the steak and then the salsa. Garnish with cheese and a few cilantro leaves. Enjoy!