Combine the lime juice, garlic powder, ground cumin, chili powder, and salt in a shallow dish. Add the fish, turning to coat both sides. Let marinade in the refrigerator for at least 5 minutes.

Combine all of the ingredients for the avocado cream in a small bowl and refrigerate until ready to serve.

Cook fish in a non-stick skillet sprayed with cooking spray over medium heat for about 5 minutes, flip and cook an additional 3 or 4 minutes or until the fish is cooked through.

While the fish is cooking heat a small non-stick skillet over medium heat and warm tortillas about a minute or so on each side. (I warm them one at a time, spraying both sides with cooking spray, this helps them not be too dry.) You could also wrap them in aluminum foil and place them in a warm oven.

Spread your tortillas with avocado cream. Break fish in small pieces and divide among the tortillas. Top with cabbage and tomatoes.