Even the Michelin judges will be greeted with open suspicion when they venture into the newest cordon bleu restaurant to grace Sutton.
The Clink at High Down Prison, funded by £270,000 in charitable donations, is the first commercial eaterie to open behind bars in Britain.
David Hanson, the Justice Minister, joined adventurous gastronomes who went to huge lengths to attend the official launch last week.
The select clientele had to undergo stringent body searches before being escorted past reinforced steel doors to the lavish 50-seat venue.
Inside, they were pleasantly surprised to discover computer-controlled mood lighting and a menu offering haute cuisine, such as griddled feather steak with Béarnaise sauce.
Only the plastic cutlery, arrayed on glass-topped steel tables, attested to the medium-security setting.
Mr Hanson told his captive audience: “Any of us, if you had transported us here and dropped us into this restaurant, would think we were in the West End or a quality area of town.
“It looks like what it is - which is a fantastic, professional restaurant.
“But the key for me is that prison is not just about punishing criminals, although society expects that.
"It’s also about what we do to prepare them for the life they will have outside prison in due course.”
A Ministry of Justice spokesman added: “There are easy jokes about doing porridge, or thyme served, but a prison sentence is no joke.
"Hard time is hard fact. When a prisoner is released, he faces what seems insurmountable problems, including health, housing, family and employment.
"The Clink represents a genuine opportunity for change.”
The eaterie is being run by Al Crisci, the catering manager at High Down and a former chef at the plush Mirabelle restaurant in Mayfair.
Inmates working in kitchen will be able to gain catering qualifications while serving prison officers poached egg duchess served on a bed of spinach.
A private dining area, offering high-quality food at £50 a head, will also be open to invited charity volunteers and corporate guests interested in employing ex-offenders.
For more information call the Clink on 020 7147 6524.