2Prepare the fish marinade using yellow mustard paste, black pepper, lemon juice and a pinch of salt. Marinate the fish for 25-30 minutes and refrigerate.
3Prepare the tartar sauce: finely chop the carrot, onion, and gherkins. Mix all ingredients together, including mayonnaise, salt, pepper, paprika, and lemon juice.
4Prepare the batter: Beat egg white, add flour, salt, pepper, baking powder, turmeric, and sparkling water/7up/sprite. Mix well.
5Coat each piece of marinated fish with flour, then dip in the batter and fry in hot oil until golden brown.