In a large bowl, combine shredded cabbage and grated carrots. In a separate bowl, whisk together mayonnaise, apple cider vinegar, and sugar until smooth. Pour the dressing over the cabbage and carrots, and toss to combine. Refrigerate until ready to serve.

Prepare the Chips

Peel the potatoes and cut them into thick fries. Rinse in cold water and pat dry. Heat vegetable oil in a large pot or deep fryer to 350°F (175°C). Fry the potatoes in batches until golden brown and crispy, about 5-7 minutes. Remove and drain on paper towels. Season with salt.

Make the Batter

In a mixing bowl, combine flour, baking powder, salt, and black pepper. Gradually whisk in the Guinness until the mixture is smooth and has a thick consistency.

Fry the Fish

Dip each cod fillet into the batter, allowing excess batter to drip off. Carefully place the battered fish into the hot oil and fry for about 4-5 minutes on each side or until golden brown and cooked through. Remove and drain on paper towels.

Serve

Plate the fish alongside the chips and slaw. Serve with tartar sauce and lemon wedges on the side.