We work in a fish and chip shop and would never order one popular item

Fish and chips are celebrated as Britain's national dish and one that is deeply rooted in tradition.

However, there are numerous lesser-known secrets of the trade that only those who have grafted in it will understand. Whilst other fast food establishments like McDonald's and KFC tempt punters with "secret" menu options, the legendary fish and chip trade operates rather differently.

The crew at Poppies, a renowned chain of London chippies, has revealed the industry's best-kept secrets. Poppies derives its name from Pat 'Pops' Newland who established the chain after joining the fish and chip business at age 11, when he secured a job on the Roman Road chopping up The Daily Mirror newspaper to wrap fish and chips in for takeaway.

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Today the chain serves the great British classic in all its glory at four London sites; Soho, Spitalfields, Camden and Notting Hill. Yet even with its magnificent selection of delicious, fresh fare, there's one item the Poppies crew wouldn't be caught dead ordering.

They toldExpress.co.uk: "It would have to be jellied eels. They've been a popular dish since the 18th century and lots of our customers love them but if you're new to the dish it can be quite a demanding bite! We serve them in the traditional way which is cold having been chopped, boiled and coated in a spiced stock that sets around the pieces of eel forming a jelly."

Regarding the top sellers that the team and their patrons favour most, it simply has to be cod and chips. They're requested "all day long", revealed the Poppies crew, who disclosed that an incredible 70 per cent of Londoners prefer cod above other fish varieties.

And it's hardly surprising given Poppies restaurants' distinctive proposition - fresh, not frozen fish. The Poppies team shared: "A lot of fish and chip shops use frozen fish fillets which I don't think many people realise.

"The fillets come from far away and can be frozen a long time before they end up on your plate. It's one of the main points of difference at Poppies."

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They added: "We only ever use fresh fish, caught sustainably and responsibly from the waters around Peterhead in Scotland. Every day we receive the fresh catch, our skilled fishmongers fillet and prepare the portions and then they are coated in batter and cooked to order for our customers."

No fish and chips order is truly complete without a tasty accompaniment, and at Poppies, mushy peas reign supreme as the bestseller. The team disclosed: "Curry sauce trumps gravy amongst our customers but the number one side is always mushy peas."

These scrumptious accompaniments complement an astounding 13 tons of potatoes that get peeled in Poppies kitchens weekly to create the 40,000 chip portions purchased each week. Whilst everyone has their preferred chippy, Poppies caters to an remarkable 10,000 plus Londoners who treat themselves to fish and chips weekly.