The 24-year-old, who spent seven and a half years behind bars after being wrongly convicted of murder, also enjoyed his first taste of bacon since being locked up as a teenager.
Mr Hallam's conviction was overturned by the Court of Appeal after photographs on his mobile phone showed him miles from the scene of the killing.
Afterwards his supporters were seen spraying champagne, but the freed prisoner has disclosed how he celebrated his release by enjoying more simple pleasures - and how the taste of freedom has affected him.
He told The Sun: "It was scary. I'm still in shock but I'm just so happy to be home and I'm just happy everything's finally over now.
"Everything looks different to how I remember it. I said to my mum, how long has that skyscraper (the Gherkin) been there? I haven't even crossed a road in nearly eight years.
"The first thing I did when I got home was have some pie and mash. I've missed that. We came back to my house and about five of us just lay on the bed and cuddled while we watched Only Fools and Horses."
Mr Hallam was just 17 when he was found guilty of the murder of trainee chef Essayas Kassahun, 21, who died after being attacked by a group of youths on the St Luke's estate in Clerkenwell, London, in October 2004.
But he has always insisted he was never at the scene and his conviction was formally quashed yesterday in a ruling by Lady Justice Hallett, Mr Justice Openshaw and Mr Justice Spencer.
In a statement read afterwards Mr Hallam said: "I don't want anyone else ever to suffer what I've been through since 2004.
"The identification evidence against me was so unreliable that it should never have been put to the jury.
"I now need time to recover with my family and friends from the nightmare I have been through for seven-and-a-half years.
"Justice has long been denied to me but it has now finally prevailed."
Barrister Henry Blaxland QC said Mr Hallam, of Hoxton, east London, was the victim of a "serious miscarriage of justice".
His family and friends have waged a high-profile campaign insisting he is innocent, with supporters including the actor Ray Winstone.
Mr Hallam sat in the public gallery with his mother Wendy Cohen as the judges gave their reasons for their decision.
There was tumultuous applause and shouts of "justice" as the conviction was quashed.
Lady Justice Hallett gave the court's reasons in a judgment lasting more than an hour.
Mr Hallam's conviction was overturned in the light of fresh evidence relating to his alibi and identification.
His case came before the appeal judges after it was referred to the court by the Criminal Cases Review Commission (CCRC), the independent body which investigates possible miscarriages of justice.
At his trial, prosecutors had relied heavily on the disputed testimony of two witnesses, who claimed to have spotted Mr Hallam at the murder scene. He was jailed for life and ordered to serve a minimum term of 12 years behind bars.
But Mr Hallam, a kitchen fitter, who dreamed of pursuing a career in the Army, always maintained his innocence, insisting he had been playing football half a mile away with a friend at the time of the killing.
His lawyers told the Court of Appeal that the original police investigation had been fatally flawed, with officers failing to check out his alibi and the prosecution failing to disclose potentially crucial evidence including mobile phone data and CCTV footage.
The hearing had been due to last two days but amid emotional scenes, Mr Hallam, was told he was to be freed immediately on bail after the prosecution indicated they would not oppose his appeal against conviction.
In 2007 his first appeal against conviction was dismissed, but the following year it was announced that the Criminal Cases Review Commission (CCRC) had ordered a review of the case.
Officers from Thames Valley police undertook a fresh investigation of the evidence first collected by the Metropolitan Police.
Their subsequent report claimed to have unearthed new evidence which cast doubt on the original conviction.
Two witnesses claimed to have seen Mr Hallam at the scene of the murder near Old Street, where a mob of youths had attacked Mr Kassahun.
But one later withdrew her evidence telling the court: "I was just looking for someone on the spot to blame."
Of the seven people originally charged in connection with the killing, only Mr Hallam and another man, Bullabeck Ringblong were convicted.