Mix flour with favorite spices such as garlic powder, red or black ground pepper. Stir the flour mixture into the beer and mix until well blended.
Wash fish by dipping in cold, lightly salted water or water with a little bit of lemon juice added. Be sure fish is completely dry before dipping into batter.
Prepare salsa; reserve.
Put the vegetable oil into a deep skillet and bring to 375 F. Place fish in a single layer -do not let pieces touch each other. Cook fish until batter is crispy and golden brown.
Heat corn tortillas lightly in a skillet or Mexican comal until they are soft and hot.
To assemble, on each tortilla layer the fish fillet, white sauce, salsa and cabbage. Top it off with a squeeze of lime. Fold tortilla over to serve.