Battered Market Fish Bun Recipe

Combine the white wine vinegar, water, sugar, salt and fennel seeds (if using) in a small saucepan and bring to a simmer so the sugar and salt dissolve.

Place the thinly sliced fennel in a heatproof jar or bowl and pour the hot pickling liquid over it. Press the fennel down so it is submerged, let cool to room temperature (about 20 minutes), then cover and refrigerate for at least 30 minutes. Can be made ahead and kept up to 1 week.

Place shredded cabbage in a bowl, sprinkle with kosher salt and sugar. Massage the cabbage with your hands for 2–3 minutes until it softens and releases a little moisture.

Add rice vinegar and neutral oil, toss to combine. Taste and adjust salt/vinegar. Let sit for 10–15 minutes while you prepare the rest so flavors mellow.

In a small bowl combine Greek yoghurt, mayonnaise, chopped cornichons, chopped capers, dill, lemon juice and zest. Season with salt and pepper and stir until smooth. Chill until ready to use.

Pat fish fillets dry with paper towel and cut into four portions (about 4 oz each). Season lightly with 1/2 teaspoon salt and a pinch of pepper.

Lightly dust each fish piece with the extra 1/2 cup flour, shaking off excess—this helps the batter adhere.

In a bowl whisk together 1 cup all-purpose flour, 1/4 cup cornstarch, 1/2 teaspoon baking powder and 1 teaspoon salt and 1/4 teaspoon pepper. In a separate small bowl beat the egg, then add the cold sparkling water and stir to combine. Pour the wet ingredients into the dry and whisk briefly—do not overmix; some lumps are fine. Batter should be thick enough to coat but still slightly runny; if too thick add up to 2 tablespoons more sparkling water.

Pour vegetable oil into a heavy-bottomed skillet or pot to a depth of about 1 inch and heat to 350°F (175°C). If you don't have a thermometer, test by dropping a small bit of batter; it should sizzle and float immediately.

Working in batches, dip each floured fish piece into the batter, allowing excess to drip back into the bowl, then carefully lower into hot oil. Fry 3–4 minutes per side (or 5–6 minutes total) until the batter is golden brown and fish is cooked through (opaque and flakes easily). Don’t overcrowd the pan. Drain on a wire rack set over a sheet tray or on paper towels.

Split buns and spread a little butter on the cut sides. Toast cut-side down in a dry skillet over medium heat until golden, about 1–2 minutes.

Spread about 1 tablespoon of yoghurt tartare sauce on the bottom bun. Top with a generous pinch (about 1/4 cup) of salted cabbage, then place a piece of battered fish on top.

Add a tablespoon of pickled fennel (drained) and another drizzle (about 1 teaspoon) of tartare sauce if desired. Cap with the top bun.

Serve immediately with lemon wedges on the side for squeezing over the fish.