To prepare slawsa, combine cabbage along with onion, tomato, and cilantro in a bowl. Add lime juice and salt and pepper to taste and toss to coat.
For cream sauce, whisk together sour cream, yogurt, cilantro, and lime juice until smooth and no lumps remain. If desired, add a teaspoon or two of water to thin it to a drizzling consistency.
Wrap tortillas in aluminum foil and place in a 250 degree F oven until warmed through.
Meanwhile, preheat a nonstick skillet over medium heat. Season both sides of fish with chili and garlic powder, and a generous pinch of salt and pepper.
Cook fillets until browned on both sides and center is opaque (internal temperature should read 135 degrees F), about 3-5 minutes per side depending on the thickness of your fillets. During the last few minutes of cooking, break up the fish with a spoon or spatula into bite-sized flakes.
Place warm tortillas on serving plates. Spoon fish down the middle of tortillas. Top with a generous mound of slawsa and a drizzle of cream sauce, as well as additional fresh cilantro as desired.
