A lamprey pie is being sent to the Queen to celebrate her becoming Britain's longest reigning monarch.
Dr Fosters Restaurant in the city has made the dish using eels from Canada as they are a protected species in the UK.
The centuries-old tradition has seen pies made in distinctive shapes, such as a cathedral in 2012 to mark the Queen's Diamond Jubilee.
This year's pie was also shaped as a cathedral but, according to the baker, also reflected the city's diversity.
Restaurant owner Dawn Melvin, said: "I think we're a multi-cultural city, I think this represents everyone in the city - not just the cathedral but every ethnic part of the community which is important to us."
Mayor of Gloucester, councillor Sebastian Field said: "We're pleased to send the lamprey pie with our warmest wishes and our grateful thanks for Her Majesty's long and devoted service to our nation."
Lampreys are an ancient and primitive group of jawless vertebrates and have long, eel-like bodies that lack scales.
At about 17:30 BST Queen Elizabeth will have reigned for 23,226 days, 16 hours and approximately 30 minutes - 63 years and seven months, surpassing Queen Victoria's record.
The pie was presented to the Lord-Lieutenant of Gloucestershire Dame Janet Trotter by the city mayor, councillor Sebastian Field on Wednesday morning.
A frozen pie will be taken to London on Thursday.
Dame Janet said the dish was a "great delicacy" which is sent to the monarch on "great occasions".
"It looks absolutely fantastic. It took 30 hours to make", she said adding the lampreys are "curious and horrible" creatures.