Former MasterChef contestant Matei Baran, of the Salt Cove in Tynemouth, was drawn into a row with the chain.
A cook claims he was ordered to change the name of the charity recipe book he wrote in honour of his severely ill son.
Former Professional MasterChef quarter-finalist Matei Baran penned a cookbook, originally entitled 'Big Chef, Little Chef', to raise money for The Cystic Fibrosis Trust.
Matei's six-year-old son, Armin, suffers from cystic fibrosis himself.
Rushed into surgery just after he was born, little Armin underwent three operations in the month after he was born, spending the first six months of his life in hospital.
He still battles serious problems with his lungs and guts and has to take hundreds of pills every week.
But "happy, brave" Armin still leads an active life - and loves spending time in the kitchen with his dad.
Matei, head chef at Salt Cove, in Tynemouth, said: "My little boy is my inspiration and I've wanted to do this for years.
"The name was so simple: me being the Big Chef and Armin being the Little Chef."
Matei knew the phrase 'Big Chef Little Chef' had previously been used in a Gordon Ramsay TV show, so he checked for copyright.
Finding the phrase hadn't been claimed, he applied to register the trademark, paying £600.
But he was shocked to receive a letter from roadside restaurant chain Little Chef, insisting his planned name was too close to their own title.
"Nobody had the whole name and I had thought, if they did, I would explain what I was doing and that it was for charity and 100% they would understand and let me use it, just for this book," Matei said.
"Little Chef didn't have the whole name trademarked, but they said their customers would get 'confused' if I used it.
"In the end I offered to give up on the trademark but still use the name for the book, but they wouldn't let me, and I can't afford to fight it.
"It's for charity, I'm not making any money from it: all the profits after costs go to The Cystic Fibrosis Trust. I was really surprised that they reacted like this."
Writing to Matei, Little Chef said it wasn't relevant that the enterprise was for charity, because using the phrase "little chef" would "dilute the distinctiveness" of their brand, and was their trademark.
In a letter to Matei, Edwin Coe LLP said it had filed a Notice of Threatened Opposition against Matei’s trade mark application and warned him: "If you do not immediately: (i) withdraw your UK trade mark application and (ii) cease all use of our client’s “Little Chef” mark, our client will have no option but to formally oppose your UK trade mark application and to take all other action necessary against you to protect its valuable intellectual property rights."
It added: "We would encourage you to change the name of the book now so that it does not contain the words “Little Chef” before our client is forced to escalate matters against you, the publisher and/or any other third parties."
Matei had already had posters and other material printed, which he had to scrap and replace with new materials with a changed name - taking more cash from the potential profits from the charity.
"If I had had to send it back to the printers, that would have been it," he said.
Despite the row, Matei says he's still excited for the project, now entitled 'Big Chef, Mini Chef', which will be launched at Seven Stories in Ouseburn on January 26.
He said: "The idea is both to raise money for the charity and encourage people to cook with kids. All the dishes are presented a bit more like in a restaurant, because I think perhaps kids will see that sort of cooking perhaps want to be part of the restaurant industry when they grow up.
"The recipes are quite straightforward, they bring food to kids and make it exciting. Just little things, like adding an edible flower, or dipping things in chocolate, can make it really fun for them to get involved."
Children from across the North East were involved in the creation of the book, joining Armin and Matei for cooking parties and photoshoots to create the food and images used. Children from County Durham special school Hopewood Academy enjoyed getting involved so much that they had two whole pages dedicated to their recipes.
Outgoing Armin, who loves horse riding and taekwondo, loved taking part in these parties, his "very, very proud" dad said, and is now looking forward to seeing the published book.
Little Chef has been contacted for comment.
Copies of Big Chef, Mini Chef will be available at https://mateibaran.com/products/big-cook-mini-cook