If there is one man who doesn't need PR, it's Jamie Oliver. A chef who has sold 14 million books and who is worth an estimated £65m, the boy from Essex has certainly done good since he burst on to our screens as The Naked Chef at the end of the Nineties.

Next Monday, Oliver opens his 18th Jamie's Italian restaurant at the top of Park Street, opposite Bristol University.

A collection of restaurants that launched in Oxford in 2008, Jamie's Italian can now be spotted on high streets across the UK, as well as Sydney and Dubai.

Informal family restaurants serving simple, classic Italian cuisine at an affordable price – albeit with a quirky Jamie twist – Jamie's Italian is produce-driven and prides itself on making its own bread and pasta. In short, this is an operation that gives restaurant chains a good name and its launch in Bristol next week has created the biggest buzz for years.

Although Jamie is currently filming in LA, he has kept in close contact with the team that has been responsible for transforming the Grade-II listed former Blackwell's bookshop into a three-floor restaurant with its own antipasti counter, fresh pasta machine and "flour station" where the bread will be made fresh every day.

On the ground floor, there is a delicatessen area where you can buy Jamie's books, kitchen products and some of the ingredients to cook at home.

The Bristol restaurant has employed almost 100 staff, many of them local, and they have been undergoing rigorous training for the past couple of weeks.

The man responsible for training the chefs is Jamie's long-term mentor Gennaro Contaldo, the Italian chef who has become a celebrity in his own right through his own restaurants and books.

Amalfi-born Contaldo is widely regarded as the man who discovered Jamie. When the cheeky boy from Essex was just 15, he tapped on the door of the Neal Street Restaurant (where Contaldo was head chef for owner Antonio Carluccio) and asked for a job.

Contaldo says he remembers the day as if it was only yesterday and although he admits to being immensely proud of what Jamie has gone on to achieve, he says he only pushed the teenager in the right direction.

"I'm so proud of Jamie I could cry every single day," he tells me in his thick Italian accent.

"But he was a talent already – I just pushed him, taught him about the Italian food and culture and gave him the passion.

"Jamie was a very young boy when he came to me and he really wanted to learn how to cook Italian food.

"He had heard that I had a vacancy for a pastry chef and he turned up at the kitchen door about 7am the next morning.

"I got a knock on the door and he just said 'hello, I hear you are looking for a chef'. I asked him if he had any experience and he said 'oh yeah, I can do this and that' – even though he had only been to college and worked at his dad's pub.

"We usually asked for references but there was something about him. I just knew. I asked him when he could start and he said 'now' and he just walked into the kitchen. It was like he had been there all his life and working with me.

"He was working very hard, making ice creams – fantastic ice creams – and some days he would still be working at 1am in the morning and then back in first thing the next morning to learn how to make the bread, even on his days off. He just wanted to learn about everything and taste everything."

After working for Contaldo at Neal Street, Oliver moved on to River Cafe, which is where he was famously spotted by a film crew who were there to film the restaurant. After that, he was offered a screen test by the TV company and the rest, as they say, is history.

Fourteen million books and 23 restaurants later and Jamie is an international star, with his TV shows broadcast in more than 100 countries.

Contaldo and Jamie have remained the closest of friends throughout and his mentor describes their relationship as more like "father and son".

"I speak to Jamie every day and he is very excited about opening in Bristol, which he knows quite well and which has had a place in his heart for a long time.

"And what an amazing site we have here opposite the university. At first, I thought it was a church so I went in for a look around. I've been sending Jamie loads of pictures of the Bristol site as it has progressed and he will be down to see it as soon as he can. He goes to every single restaurant – nobody knows when, he just turns up and often he puts his chef's jacket on and helps the chefs in the kitchen.

"The first thing he asked me when I phoned him from Bristol was if I looking after everybody – he never refers to his team as staff, he refers to them as his family.

"When you work for Jamie, you belong to his family. He has a love and passion for every one and he makes sure every one is well looked after.

"Nothing has changed since the day I met him, it's incredible. Jamie always has time to speak to everyone and he still loves learning about food and people."

The whole idea about Jamie's Italian is that it offers people good value Italian cooking in an informal, funky atmosphere.

The menu includes antipasti around £3-£5, pasta dishes between £6 and £10 and meat and fish main courses between £10 and £16. As well as a cocktail list, there is an all-Italian wine list starting at £15.35 a bottle or £4.25 a glass.

Highlights of the menu include grilled lamb chops with creamy artichoke and mint sauce, roasted nuts, chilli and fresh mint; shell-roasted Brixham scallops with pancetta, tomato salsa, shaved fennel and lemon salad; rabbit ragu pappardelle; cockles linguine, and "ultimate" chocolate, raspberry and Amaretto brownie.

The menus were devised by Contaldo with Jamie, who work closely with executive chef Jules Hunt and managing director Simon Blagden.

Since the first Jamie's Italian opened in Oxford in 2008, it has gained praise from customers and critics, many of whom cite it as the best of the many Italian restaurant chains on the high street.

Contaldo puts this down to the fact that the staff are so well trained, but also because the food is created with fresh produce and the very best ingredients.

"The idea behind Jamie's Italian was simply doing classic Italian recipes with a Jamie twist, everything had to be made with fresh ingredients and the staff have to know where everything comes from.

"We use the best flour, the best meat, the best fish, the best chicken and we want to know all about the produce – who grows the vegetables, who reared the chickens, how they were fed and if they had a happy life. If we don't have that story, we don't want to know. Our olive oil comes from Puglia, from trees that are 500 years old. You aren't going to taste better olive oil and you can taste the passion of the growers in every drop.

"We care about what we give to the people who come to our restaurants and we care for every member of staff. We make sure every member of staff has tasted every single dish on the menu and tasted every wine.

"If you've got the best ingredients, you have to cook it simply and simplicity can be a very hard thing for some chefs to grasp."

The success of Jamie's Italian is also down to consistency and making sure a dish you tasted at the Oxford or Cardiff branch is just as good as the one in Bath or now Bristol. Contaldo says: "I visit one of the restaurants every day but there is a daily meeting in every restaurant with the chefs and the managers and we do a cook-off to show everybody what each dish should taste like and look like.

"We make sure the staff are well informed and you can sit at a table in any Jamie's Italian and ask them anything about the menu and they will know.

"Jamie himself has visited restaurants even when he was busy. He came down to Oxford in the middle of filming to tweak the lasagne recipe until it was perfect.

"He's passionate about cooking and he always wanted to be able to create jobs for young people. He always wants to help others."

With more and more TV projects, some people may think Jamie is overstretching himself, but he employs hundreds of people to run his business and, according to Contaldo, it is no longer just about making money.

"Every business is about making money, but with Jamie it's not about that. Do you think Jamie needs all these restaurants? I don't think so. Do you think I need to do this at the age of 62? I don't think so.

"We do this because we want to get people eating well and enjoying it. It's also about giving young people opportunities. Jamie just wants to give something back to people and that's what's important to him.

"When he worked in my restaurant before he did television, he said to me 'one of these days, I'm going to become very famous and make a bit of money and I'm going to open restaurants all over the world and you will be working with me in every one of them'.

"Years later, he approached me about Jamie's Italian and reminded me of that conversation. He said that was a dream then so let's make that dream come true now.

"I've been in the kitchen every day for the past 52 years and I still enjoy every single day. I'm proud of Jamie and I'm now proud to be representing him through Jamie's Italian."

Jamie's Italian opens on Park Street on Monday, February 28. For Mark Taylor's exclusive preview, see tomorrow's Post.