Prepare the Homemade Corn Tortilla dough according to its separate recipe, using 160g masa harina, 2g fine sea salt, and 200g warm water at about 40°C. Once the dough has rested, divide it into 16 equal balls of about 22g each. Keep the dough balls covered at all times so the masa does not dry out. Press each tortilla to about 11.4cm / 4.5 inches in diameter. Cook on a dry hot skillet or griddle until lightly charred, flexible, and just cooked through. Stack immediately under a towel so they steam and stay pliable. That trapped steam is exactly what keeps the tortillas soft and pliable through assembly, rather than stiffening as they cool uncovered.

In a bowl, toss the green cabbage, red cabbage, carrot, lime juice, oil, salt, and pepper. Mix well and set aside. It should stay fresh and crunchy, not heavily dressed. Keeping the dressing light, rather than heavy-handed, is what preserves the cabbage's own real crunch — an overdressed slaw softens considerably faster, working against the textural contrast this taco depends on.

In a small bowl, stir together the sour cream or Greek yogurt, mayonnaise, lime juice, garlic, cilantro, and salt. Add a little water if needed until it becomes smooth and spoonable. Set aside. Adding water gradually rather than all at once protects the crema from thinning past the ideal spoonable consistency, since it's far easier to loosen it further than to bring it back once too much liquid has already gone in.

Make your Pico de Gallo recipe separately and keep it chilled until serving.

Pat the fish very dry with paper towels, then cut it into 16 strips, each about 50–60g. Season lightly with the salt, black pepper, garlic powder, paprika, cumin, and lime juice. Let sit for about 10 minutes while you prepare the batter. Drying the fish thoroughly before it ever meets the wet batter matters directly here — any residual surface moisture would work against the batter's own ability to adhere cleanly and fry up crisp rather than soggy.

Pour neutral oil into a deep skillet, saucepan, or Dutch oven to a depth of about 4–5cm. Heat to 175–180°C. Reaching and holding this specific temperature range before frying begins is what gives the batter its best chance at frying up genuinely crisp rather than greasy — oil that's too cool lets the batter absorb excess fat before it ever sets.

In a bowl, whisk together the flour, cornstarch, baking powder, salt, pepper, garlic powder, and paprika. Pour in the cold sparkling water and whisk just until combined. It should look like a thick but light batter. A few tiny lumps are fine. Stopping the whisking the moment the batter comes together, rather than continuing until perfectly smooth, is what protects the sparkling water's own carbonation — overworking the batter knocks out those tiny bubbles that are specifically responsible for its light, crisp fried texture.

Dip each fish strip into the batter, let the excess drip off slightly, then lower carefully into the hot oil. Fry in batches for about 3 to 4 minutes, turning as needed, until the coating is deeply golden, crisp, and the fish is just cooked through. Transfer to a rack or paper towel-lined tray and lightly season with a tiny pinch of salt while hot. To keep the fish crisp but not overcooked: keep the oil at 175–180°C, fry in small batches so the oil temperature does not drop too much, use strips sized around 50–60g each, pull the fish as soon as the coating is golden and the fish flakes easily, and do not leave the cooked fish piled tightly together, or the crust will soften. Frying in properly small batches is what protects the oil's own temperature from dropping too far when cold fish is added — a significant temperature drop is exactly what would let the batter soak up excess oil rather than frying crisp.

If needed, rewarm the tortillas briefly on a dry skillet, then wrap them again in a towel to keep soft and warm.

Place a little cabbage slaw in each tortilla. Top with one piece of crispy fish. Spoon over lime crema, then add pico de gallo and fresh cilantro. Serve with lime wedges on the side. Placing the slaw down first, directly against the tortilla, gives the fried fish a slightly raised, drier base to sit on rather than settling directly against any moisture the tortilla itself might carry.