Add 1 cup mayonnaise to a small bowl and gradually stir in 2 T lime juice until consistency is slightly runny. Mix in 1 tsp minced capers, ½ tsp dried oregano, ½ tsp ground cumin, ¼ tsp dried dill weed, ½ tsp ground cayenne pepper, and ½ jalapeno pepper if desired. Cover and refrigerate.
Pico de Gallo - one hour before eating
In a small bowl, combine 2 roma tomatoes, 1 medium onion, 4 T lime juice, 2 T chopped fresh cilantro, 1 jalapeno pepper, and salt and pepper to taste. Cover and refrigerate.
Beer Batter
Heat oil in deep-fryer to 375°f
To make beer batter: In a large bowl, combine 1 cup all-purpose flour, 2 T cornstarch (check out this no-GMO brand), 1 tsp baking powder, and ½ tsp salt.
In a small bowl, whisk together 1 egg and 1 cup beer.
Quickly stir the beer and egg mixture into the flour mixture to make the beer batter. Some lumps are normal.
Cook the Fish
Place 1 cup all purpose flour in a medium size bowl, Dust fish pieces lightly with flour, shaking off excess.
Dip each fish piece into beer batter, allowing excess to drip off, then carefully lower into deep fryer. Don't overcrowd fryer.
Fry fish until crisp and golden brown, fish should be 140℉.
Remove from deep fryer and drain on paper towels.
Serve
If needed, lightly heat tortillas one by one in a warmed skillet, just a few seconds to make pliable.
To serve, place shredded cabbage on the tortilla and top with fish, pico de gallo, and white sauce.
Notes
If time is a concern, you can use good quality frozen beer battered fish fillets, taking out the fish, batter ingredients, and those instructions.