To make the beer batter, in a bowl, stir together the flour, garlic salt, and ground chile. Pour in the beer, whisking until smooth. Cover and let stand for at least 10 minutes and up to 1 hour.

Meanwhile, make the creamy sauce. In a small bowl, stir together the mayonnaise, ketchup, and yogurt until blended. Set aside.

To make the tacos, remove the skin from the fish fillet if it is still intact and run your fingers over the fillet to check for and remove any embedded bones, using tweezers or needle-nose pliers if necessary. Cut the fish into 8 strips, each 3-4 inches (7.5-10 cm) long and 3/4 inch (2 cm) wide, and place in a nonreactive bowl. Sprinkle with the lime juice, garlic salt, and ground chile and toss to mix.

Let marinate at room temperature for 10 minutes. Pour the oil to a depth of 1 inch (2.5 cm) into a heavy pan with tall sides and heat to 375°F (190°C) on a deep-frying thermometer.

Meanwhile, heat a comal, griddle, or heavy frying pan over medium heat. When it is hot, stack 2-3 tortillas on the heated surface and leave for a few seconds.

Flip the tortillas, rotating them every second or so until all are hot. Wrap in a dry kitchen towel and repeat with the remaking tortillas. They should keep warm for about 10 minutes. If they are to be held longer, wrap a damp towel around the dry towel and place in a 200°F (95°C) oven.

Pat the fish dry with paper towels. One at a time, dip a strip into the batter, allowing the excess to drip off, and slip into the hot oil. Do not allow the pieces to touch. Fry until the strips are crisp and golden, about 7 minutes. Using a slotted spatula, transfer to paper towels to dry. When all are fried, transfer to a warmed serving plate. Put the salsa, cabbage, and lime quarters in separate small bowls and set on the table along with the fish, creamy sauce, tortillas, and hot pepper sauce. Let the diners make their own tacos, wrapping the fish in a tortilla and adding the other ingredients.