Sam Stern has never been afraid of challenges. In the past 12 months, the 15-year-old has persuaded a generation of his peers to make everything from moules marinière to pre-exam hot chocolate, with his best-selling book, Cooking up a Storm.

Now, after a television career which had been limited to the friendly studios of Blue Peter and This Morning, he is making his biggest career move yet, by taking his talents to America.

Sam, whose career in the kitchen began when his brother, Tom, started texting him from university to ask for family recipes, left for New York last week with his mother and co-writer, Susan, and has since been plunged into a whistlestop tour of television studios, which has seen him reach a prime slot on NBC's popular Today show and The Martha [Stewart] Show.

Magazines of every hue have also been lapping up the idea of the "British boy who cooks", with 17, Sweet 16 and Cosmo Girl on the itinerary. Yesterday he left Los Angeles for Chicago and he returns to the family home in northern England next week.

"Almost every kid knows how to work a refrigerator, some know how to work a microwave. But this kid can cook," NBC viewers are told, before Sam arrives to say that the key to cooking is "to have fun, to show you're having fun and to have a laugh."

Among the recipes he demonstrated live were pasta and chicken wrapped in parma ham and garlic, and herb cream cheese wrapped in parma ham.

"The American audiences have been hugely enthusiastic," said Sam's father, Jeffrey. "There's been a lot of interest in the idea of someone young being interested and talented."

Sam and his mother's publishers, Walker Books, have made a targeted approach to the US market by producing an Americanised version of Cooking up a Storm, with American measurements.

The original book - which was divided into lifestyle rather than ingredient-led chapters, including "School Recovery" (flapjacks, vanilla shortbread), "Evening chill out" (spaghetti bolognese, cauliflower cheese), and "Impress the girls" (guacamole, houmous) - went down a storm.

Written at a time when children were being asked to think about the merits of what they ate and drawing on Sam's apprenticeship, which began with rolling dough at the age of three and moved on to making "roast chicken with loads of herbs" at the age of nine, it seemed to hit the right note. In his own words, the cookbook was based on "the sorts of things that my mates and I like to eat." The book earned plaudits from Jamie Oliver.

Sam - or Little Chef as he is known at school - said before leaving for the US that he could spend hours "blitzing, whisking and mixing.'' He said: "I find all that activity is really relaxing. I love all the technical stuff that goes with cooking - how to make batters, pastry, bread, sauces, soups. Once you can do it the way that it says in the book you can then get more creative.''

The US problem with childhood obesity seems to have played its part in his reception there. "There is a philosophy behind the book about eating well to feel well," said Mr Stern. "That does seem to have been appreciated out there."

On his return to Britain, Sam and his mother have their next two publications to tackle. Real Food, Real Fast - published in October - is aimed at children who want good food in a hurry. That will be followed by another book on food for young people who are leaving home and have to fend for themselves.