Mr Wilson, meticulous about his condition, had asked for a chicken tikka masala with “no nuts” but his curry from the Indian Garden, Easingwold, was cooked with a groundnut mix containing peanuts.
The prosecution alleged Zaman, said to have almost £300,000 of business debts, switched from almond powder to the cheaper ingredient to cut costs. He did that despite warnings of the dangers to people with allergies.
Judge Simon Bourne-Arton, the Recorder of Middlesbrough, said Zaman had made a success of himself since coming to this country 40 years ago, building up his businesses and gathering a property portfolio worth more than £2 million.
“You threw all that away,” the judge said. “You have done so in pursuit of profit.
“You have done so in such a manner as to bring about the death of another individual.
“Paul Wilson was in the prime of his life.
“He, like you, worked in the catering trade. He, unlike you, was a careful man.”
The judge said Zaman ignored warnings from officials after 17-year-old Ruby Scott suffered a reaction to a curry, three weeks before Mr Wilson’s death in Janury 2014.
He could have destroyed the groundnut mix then, but decided to continue to use it at his restaurants.
The judge said Zaman had told “many lies” to the jury, adding: “You remain in complete and utter denial for what you have done.”
This was not a “transitory” case of gross negligence, but one lasting seven months – from his fateful decision to switch almond for groundnut in June 2013.
The judge acknowledged Zaman was of good character, and the sentence would have an impact on his wife and four children.
Mr Wilson had eaten very little of the curry and he was found slumped in the toilet at his home in Helperby by his housemate. He died from a severe anaphylactic shock.
After the verdict, the Crown Prosecution Service (CPS) said it showed that food suppliers had a duty of care towards their customers.
Zaman, who owned six restaurants in York and North Yorkshire, cut costs by using the cheaper ingredient and by employing untrained, illegal workers.
The prosecution said the owner had “put profit before safety” at the restaurants he owned.
Zaman denied manslaughter by gross negligence, perverting the course of justice and six food safety offences. He was found guilty of all charges except perverting the course of justice.
He claimed he left managers to run his restaurants and that included ordering stock and hiring staff. He was not on the premises when the curry was sold.
Richard Wright QC, prosecuting, said: ” His was a reckless and cavalier attitude to risk and one that we, the prosecution, would describe as grossly negligent.”
Mr Wilson’s parents, Keith and Margaret, from Sheffield, said their son had carefully managed his condition since he was seven when he had a reaction to a Marathon chocolate bar.
He loved curry but was always clear when ordering that his food must not contain nuts.
They said: ” Don’t let this happen again.”
Outside court, Detective Inspector Shaun Page said Mr Wilson’s death was “totally avoidable”.
He added: “We have shown Zaman had a duty of care to serve safe food. He has breached that duty to a criminal standard.”
Martin Goldman, chief crown prosecutor with CPS Yorkshire and Humberside, warned restaurant bosses: ” If you ignore your responsibilities and regulations and put lives at real risk then we will not hesitate to prosecute.”
Alistair Webster QC, defending, said Zaman was a hard-working family man with no previous convictions.