For the sea bass: If you buy packaged fresh fillets, then there is no need to wash them again. Just touch its flesh to see if there are any tiny leftover bones, then use a tweezer to pluck them out.

For the green lettuce: Roughly chop the lettuce, wash it clean, then spin dry in a colander or use a paper towel to pat dry.

For the cabbage: Rinse the cabbage and pat dry using a paper towel, then cut it in half. Keep cutting each half into halves again, then cut to remove the white stem off of the four quarters. Finally, slice each quarter into shreds.

Marinate the sea bass: Season 18 oz sea bass with 1/4 tsp salt, 1/2 tsp pepper, 1/2 tsp paprika, and 1 tbsp olive oil.

Mix the butter with breadcrumbs: Add 1/2 cup plain panko breadcrumbs and 1 1/2 tbsp unsalted butter to a small bowl, then mix well.

Mix the egg with water: Add 1 medium egg and 1 fl oz water to a small bowl, then stir to combine.

Coat the sea bass with flour, egg, and breadcrumbs: Coat each fillet in a thin layer of 2 tbsp flour, then egg, and finally breadcrumbs.

Cook the sea bass: Place the fillets inside an air fryer and cook at 375 °F for 15 minutes.

Make the sauce: Add 2 tbsp Japanese mayonnaise, 2 tbsp Heinz ketchup, and 1 tbsp plain Greek yogurt to a small bowl, then stir to combine.

Halve and cook the burger buns: Cut each bun into halves, then spread a layer of butter on the cut surface of each half. (1 1/2 tbsp butter for all 4 buns) Next, air-fry the halves at 350 °F for 3 minutes.

Assemble the burger: Start with the bottom bun, add lettuce, shredded red cabbage, tomato slices, red onion, sea bass, sauce, parsley, and finally the top bun.