Start by preparing the sauce. In a small bowl, whisk together the mayonnaise, sour cream, lime juice, cilantro, minced garlic, salt, and pepper. Set aside to let the flavors meld.

Prepare the fish by cutting the fillets into small, manageable pieces that will fit inside the tortillas. Pat the fish dry with paper towels.

In a shallow dish, whisk together the flour, chili powder, garlic powder, cumin, paprika, salt, and black pepper. Gradually whisk in the beer until the batter is smooth and free of lumps.

Heat vegetable oil in a large skillet or deep fryer to about 350°F (175°C).

Dip each piece of fish into the batter, allowing any excess to drip off. Carefully place the battered fish into the hot oil and fry until golden brown and crispy, about 3-4 minutes per side. Cook the fish in batches, if necessary, to avoid overcrowding the skillet.

Once cooked, transfer the fish to a paper towel-lined plate to drain excess oil.

Warm the corn tortillas by heating them on a dry skillet over medium heat for about 30 seconds on each side, or until they become pliable. Alternatively, you can wrap them in a damp kitchen towel and microwave them for 1-2 minutes.

To assemble the tacos, place a few pieces of fried fish onto each tortilla. Top with shredded cabbage or lettuce, diced tomatoes, chopped cilantro, and diced onions.

Drizzle the prepared sauce over the toppings. Squeeze fresh lime juice over the tacos for added brightness.

Serve the Baja-style fish tacos immediately, accompanied by extra lime wedges. Enjoy!