Step 1: Marinate the Fish
Place cod fillets in a shallow bowl and pour the buttermilk over them.
Let them marinate for 15–20 minutes to help the coating stick and enhance tenderness.

Step 2: Make the Tartar Sauce
In a small bowl, combine mayonnaise, chopped pickles or relish, Dijon mustard, lemon juice, salt, and pepper.
Stir until well mixed. Cover and refrigerate to chill while you prepare the rest.

Step 3: Mix the Slaw
In a separate bowl, toss shredded cabbage and carrots with mayonnaise, apple cider vinegar, honey (or sugar), salt, and pepper.
Mix until everything is evenly coated. Set aside or chill until ready to assemble.

Step 4: Prepare the Breading
In a shallow dish, whisk together flour, cornmeal, garlic powder, onion powder, paprika, cayenne (if using), salt, and black pepper.

Step 5: Heat the Oil
Add 2 inches of oil to a deep skillet or Dutch oven.
Heat over medium-high heat to 350°F (175°C). Use a thermometer for best results.

Step 6: Bread the Cod
Remove cod fillets from the buttermilk, allowing excess to drip off.
Dredge each piece in the flour-cornmeal mixture, pressing lightly to coat well on all sides.
Place on a plate and let rest for 5 minutes while oil finishes heating.

Step 7: Fry the Cod
Carefully lower the fillets into the hot oil.
Fry in batches for 4–5 minutes per side, or until golden brown and cooked through.
Transfer to a wire rack or paper towel-lined plate to drain.

Step 8: Toast the Buns
Slice and toast the buns in a dry skillet or under a broiler for 1–2 minutes until lightly browned.
This helps keep the sandwich from getting soggy.

Step 9: Assemble the Sandwiches
Spread tartar sauce on both halves of the bun.
Layer with lettuce and tomato slices if using.
Add one fried cod fillet per bun.
Top with a generous scoop of slaw and a few pickle slices if desired.
Close the sandwich with the top bun and serve immediately.