PreparationPrepare and Cut Fish: Remove any pin bones from fish fillets (using tweezers makes this easy). Cut each fillet in half lengthwise. Cut each half on a diagonal into 1" strips. (Work with the natural shape of the fish as you cut; this will help the pieces stay together instead of falling apart when frying.) Make Batter: Whisk all-purpose flour, rice flour, and salt in a medium bowl. Gradually whisk in club soda until no lumps remain; adjust with more club soda or rice flour as needed to make it the consistency of thin pancake batter—it should be pourable, but thick enough to coat the fish. Heat Oil: Fit a large pot with a deep-fry thermometer and pour in oil to measure 2". Heat over medium-high heat until thermometer registers 350°. Batter and Fry Fish: Working in batches of 5–7 pieces at a time, coat fish in batter, letting excess drip off, then carefully place in oil (to avoid splattering, lower fish into oil pointing away from you). Don’t overcrowd the pot: The oil temperature will drop dramatically and fish may stick together. Fry fish, turning occasionally with a fish spatula or slotted spoon and maintaining oil temperature at 350°, until crust is puffed, crisp, and golden brown, about 5 minutes. Transfer to a wire rack set inside a rimmed baking sheet; season immediately with salt. Warm Tortillas: While fish is frying, use tongs to heat tortillas one at a time directly over a gas burner, moving them often, until lightly charred and puffed in spots, about 1 minute per side. Transfer to a plate; cover with a clean kitchen towel to keep warm. (If you don’t have a gas stove, wrap up a stack of tortillas in a sheet of foil and heat in a 350° oven until warmed through.) Serve! Top tortillas (we like two per taco) with fish, slaw, hot sauce, avocado, cilantro, and pickled jalapeños. Serve with lime wedges.