Start with the slaw: In a large bowl, combine the shredded cabbage and sliced red onion. Pour over the yogurt and lime juice, season with salt and pepper, and toss well. You want every strand coated but not swimming in dressing — the sound of the cabbage being turned over is a satisfying rustle. Set aside for at least 15 minutes to soften slightly. Stir through the coriander just before serving.

Get the oil ready: Pour the oil into a deep, heavy-bottomed pan or a deep-fat fryer — it should be about 5cm deep. Heat it to 180°C. If you don't have a thermometer, drop a cube of bread in; it should sizzle and turn golden in about 45 seconds. The oil should shimmer gently, not smoke.

Make the batter: In a wide bowl, whisk together the flour, baking powder, smoked paprika, cayenne (if using), and salt. Pour in the cold sparkling water and whisk until you have a smooth, thick batter — it should coat the back of a spoon and look like double cream. The bubbles from the water are what create that light, lacy crust, so don't overmix.

Prepare the fish: Pat the fish fillets dry with kitchen paper, then cut them into strips about 3cm wide. Dip each strip into the batter, letting any excess drip off — you want a thin, even coating. The batter will look pale and slightly frothy at this stage.

Fry in batches: Carefully lower 4-5 pieces of fish into the hot oil, ensuring you don't overcrowd the pan. Fry for 4-5 minutes, turning once, until the batter is deep golden brown and the fish is cooked through. You'll hear a lively sizzle as they go in, and the kitchen will smell gloriously of toasted paprika. Transfer to a wire rack set over a baking tray — don't use paper towels, or the crust will go soggy.

Keep the first batch warm: Pop the tray into a low oven (about 110°C) while you fry the remaining fish. The batter should stay crisp for up to 20 minutes this way.

Warm the tortillas: Just before serving, dry-fry each tortilla in a hot pan for about 30 seconds per side, until they're blistered in places and smell toasty. Stack them in a clean tea towel to keep soft and warm.

Assemble and serve: Lay a generous spoonful of lime slaw down the centre of each tortilla, top with 2-3 pieces of crispy fish, and finish with extra coriander, a drizzle of hot sauce, or a squeeze of lime. The first bite should give you a loud, satisfying crunch followed by the cool, tangy slaw.