Another word you might want to toss around is "正宗" zhèngzōng -- Authentic. Also, you might want to talk about Fish'n'Chips in English, or Chinese, or both -- to give yourself some exotic flair! (Fish'n'chips: 炸鱼薯条 Zhà yú shǔ tiáo) I work in England at an authentic Fish and Chips restaurant part time. 我在英国一家正宗的(Fish and Chips - 炸鱼薯条)餐馆做兼职工作。 Wǒ zài yīngguó yījiā zhèngzōng de (Fish and Chips - Zhà yú shǔ tiáo) cānguǎn zuò jiānzhí gōngzuò. My part time job is at a traditional British Fish'n'Chips shop. 我兼职工作是在一家英国传统的炸鱼薯条饭店。 Wǒ jiānzhí gōngzuò shì zài yījiā yīngguó chuántǒng de zhà yú shǔ tiáo fàndiàn.

我在英国传统鱼市海产店工作

炸鱼加炸土豆片？ Did it what you mean? Maybe you can express it like this "我在传统的英国炸鱼和炸土豆片的商店做兼职工作".

我在一家英式油炸品店工作。（主要卖炸鱼和薯条，欢迎品尝）。

我在一家传统的英式炸鱼和薯条店里做兼职。