Marinate the fish. Place the fish filets in a medium baking dish and season with salt and pepper. In a small bowl, whisk together the olive oil, lime zest, lime juice, garlic powder, chipotle, ancho chile powder, cumin, and cilantro. Stir well and season with salt and pepper. Pour the marinade over the fish and turn the fish pieces over in the mixture so they’re well coated. Marinate for 30 minutes.
Make the white sauce. While the fish is marinating, whisk together the mayonnaise, crema, lime juice, sugar, garlic, and hot sauce together in a small bowl. Season to taste with salt and pepper and refrigerate until ready to serve.
Prep and preheat the grill. Preheat an outdoor grill to 400-450 F. Make sure the grates are cleaned of any debris and lightly grease them with oil or nonstick cooking spray.
Grill the fish. Remove the fish from the marinade and place them on the grill for 4-5 minutes, until they have nice grill marks and release easily from the grates. Flip the fish over and grill for another 3-4 minutes, depending on the thickness of the fish filets. The fish is done when it feels firm to the touch and flakes easily.
Assemble the tacos. Assemble the tacos by flaking the fish into large chunks and layering them in the warmed tortillas with cabbage and pico de gallo. Sprinkle the cotija cheese on top and drizzle with the white sauce. Serve with lime wedges on the side.