For a time while he was growing up, Vietnamese chef Vo Duy Nam survived on scraps of glutinous rice, banh mi (Vietnamese baguette) and instant noodles given by generous passers-by.
He was then a 12-year-old working as a street peddler during his school holidays and hauling around 12kg of goods such as chopsticks and toothpicks in his hometown of Thanh Hoa in northern Vietnam.
Now 27, he is sweating it out as head chef of Avalon, a posh rooftop restaurant in Hanoi that serves Vietnamese and Western dishes such as grilled seabass with mango salsa and lemongrass beef stew.
Having thought that he would remain a street peddler for life, he is grateful for the change in his fortunes. He says through a translator: "Then, I could not think beyond surviving day to day and, now, I have an interest in fusing Vietnamese and Western styles of cooking."
He was in town last month to conduct a culinary masterclass, Flavours Of Love, which was organised by non-profit charity organisation World Vision. All proceeds from the session went towards funding the group's work in supporting poverty-ridden children in developing countries.
He presented fusion dishes such as seared duck pho roll and grilled scallops with asparagus puree, which are also served at Avalon.
Indeed, life could not be more different for him.
Of his days working as an itinerant hawker, he says he was exploited by a "trafficker who lured poor families to send their children to sell goods on the street".
While he worked hard to sell up to $20 worth of goods daily, he was paid only $45 after three months.
He says his boss also told him to pretend to be blind or deaf to sell more goods. But the toughest part of the job for him was jostling with other street children who sold the same items.
He says: "There were about 15 of us competing for the same customers. To get more business, I walked about 40km daily and went further where the competition was less intense."
He dropped out of school at 14 after his parents divorced and moved to Hanoi to become a shoeshine boy to support his mother and two younger brothers.
Working illegally in the streets, he had to keep an eye out for the police and street gangs. Home for him after a 13-hour work day was the guardhouse of a television station. A guard there took pity on him and allowed him to sleep there at night.
The turning point in his life came two years later when his friend invited him to play at a football game.
He says: "My dream was to become a footballer and I thought it was a professional training opportunity."
The session turned out to be an outreach event run by a shelter supported by World Vision. But having showed up, staff identified him as a candidate for surgery to correct his cleft lip, which had impaired his speech.
His operation was funded by World Vision and after his recovery, he stayed at the shelter, learning English and computer skills.
To "escape from the dangers of street life", he became a dishwasher at The Vine, a European restaurant in Hanoi. After a year, the head chef noticed his interest in cooking and made him a kitchen assistant before promoting him to a cook.
He says: "I wanted an opportunity to learn a new skill, but I also had to endure the head chef's hot-tempered nature. He scolded and threw my dishes away if they were not cooked properly."
Rising through the ranks in the kitchen, he was selected to take part in the high-profile reality TV cooking show, Iron Chef Vietnam, in 2012 while working at Don's Bistro, a European restaurant in Hanoi. He was part of the show's winning team, which also included his wife, a 28-year-old chef. The couple have a one-year-old son.
On his determination to succeed, he says: "My motivation comes from working for my family and not letting down the people who have supported me. I hope to open my own restaurant and write a book on my recipes and life story one day."
Grateful for the change that World Vision has brought to his life, he is a regular volunteer with the organisation, conducting talks and cooking sessions for street children in Vietnam. His wife joins him as a volunteer, cooking meals for its weekly lunch programme.
He says: "It is important to return the goodwill that I have received and I hope that my experience will inspire disadvantaged children to find their direction in life."