Season fish on both sides with salt and set aside.
Whisk together the slaw dressing ingredients in a large bowl. Add the shredded cabbage and toss to coat. Set aside.
In a shallow bowl mix together the batter, whisking to avoid any lumps.
In a large skillet (cast iron preferred), deep pot or fryer, heat oil to 350°F.
Dip fish into batter and allow excess batter to drip off. Carefully drop into hot oil. Fry fish, turning to brown both sides, 4 to 5 minutes. Remove from oil and place on a paper towel lined plate and season with salt. Repeat with all fish.
Warm tortillas over an open flame or in a dry skillet. Add fried fish, cabbage slaw and serve with lime, cilantro and salsas of choice.
Halibut is a great substitution for the cod fish. Other fish can be Haddock, Pollack, Mahi Mahi or Grouper. Cut the filets into 8 pieces.