On the surface, Jamie Oliver never seems to change. His trademark blue jeans and cowboy shirt combination, topped with blond scruffy hair, is always carefully maintained to project that affable, laddish persona we’ve come to love.

But scratch the surface and you’ll find a boy who’s grown up.

“Cook, presenter and CEO, I’m all of those. We’ve got around 6,000 staff now. Quite a lot of responsibility for a little boy from Essex,” he says, grinning widely and unable to hide his delight about the success of multiple Oliver enterprises.

Sainsbury’s may have made him a millionaire, but it’s Jamie who is keeping it that way. Last year his restaurant chain Jamie’s Italian, cooked up a 170% rise in profits, despite the recession. And he readily admits the 14 years since The Naked Chef first aired have been a huge learning curve for the former pastry chef.

Oliver’s first restaurants were not-for-profit labours of love, borne largely, he reveals, of a deep need to give something back to the public he felt indebted for his success.

“Everything went straight back to the kids. Other chefs used to say to me, ‘What do you mean it’s a charity?’ They all thought I was completely bonkers,” he recalls.

Now he’s focused on creating “healthy businesses” that are principled, offer genuine value to consumers and can help him fund more of his world-altering campaigns: “If changing hearts and minds and educating the public [with my shows] is mono, now I’m going stereo. It’s not just about informing people but giving them solutions.

“There’s less in my bank account than there was 10 years ago. It’s all out there, it’s all working, it’s all doing stuff.”

With all this in mind, he’s just developed a range of “strategic” products for the 200-year-old British frozen fish firm Young’s, that includes fish fingers, fish cakes and pies.

“Rolling up my relationship with Sainsbury’s was about giving me a bit more time to do other things,” he explains eagerly.

“It’s very easy for people to say this is just another job for Jamie… blah, blah, blah. But there are a million jobs I can do and a million I’m asked to do. And 98% of the time I say, ‘No’.

“I pick my partners really carefully and Young’s have allowed me to spec every product to over-deliver. I’ve stood by everything the public would have expected of me.”

Whether you love Oliver’s desire to transform society from the ground up, or find him a touch overbearing, his obsession with the public’s wellbeing is genuine. Though we’re just talking about the humble fish finger (albeit sustainably manufactured, economical and healthy ones) his eyes are literally shining with optimism.

“What I’ve tried to do with all my campaigns is not only make a point, but get the supermarkets and retailers to buy in. With this, I’m going further upstream and going to the producer that goes to the supermarket,” he underlines.

To be honest, it would be easy for Oliver to take his foot off the accelerator right about now. He’s got four children, a booming business empire and has helped Britain tackle deep systemic social problems, from poor quality school dinners, to battery-farmed chickens. Not to mention challenging the entrenched fast-food culture of the US in his spare time. And he does all this in the face of relentless criticism.

“As much as I’m proud of doing it, and I will continue to do it… it’s not much fun,” he suddenly blurts out while we’re chatting about filming Jamie Oliver’s Food Revolution in the States.

Although he’s still grinning, lines of sad frustration start to cross his forehead.

“I’m not going there because I need a new career, or better opportunities. I’m doing it because no one else is and the biggest network in the US is giving me a prime-time slot.

“America’s very central to food issues, whether it’s farming or business. But when I’m fighting with bureaucrats and minsters, I’m also thinking, ‘When this comes out, people are going to hate your guts’.”

After two months across the pond he’s got his feet firmly back on Blighty soil now. Yet, he admits he’s already “disenchanted” with the Coalition’s approach to food.

“The uptake of school meals has gone up in the last three years which has been a brilliant thing. And the nutritional standards I fought for, and which Tony Blair put in place, are in very good nick.”

But, he explains, local authorities are no longer required to report on take-up of school meals, as part of a recent Government move to slash red tape, and new academies don’t have to meet those hard-won standards.

“I just think there’s some stuff you mustn’t mess with,” he says, after a long pause. “And as much as I like Michael Gove, he’s so sharp and charming, I’m worried he’s baffling me with bulls**t.”

He talks about meeting the Education Minister, who told him about a wonderful academy in London that had a fantastic food policy. It was an example, Gove told Oliver, of a school setting its own high standards without interference from the State.

“I was like, ‘There was no kitchen in that school’,” Oliver explodes. “And the only reason there is, is because of a conversation I had with the guy that was paying for it, at the last hour, and persuaded him to put one in.

“Mr Gove’s telling me academies don’t need standards because they’re naturally going to do the right things… but that’s rubbish, because although a percentage will, a percentage won’t – and that ain’t good enough for our kids.”

Calming down, he takes a moment to catch his breath.

“I’m going to have to kick back into gear in the next year,” he finishes thoughtfully.

You do wonder how he’ll fit it all in, but perhaps he’ll start by taking his own advice, and pulling a few meals from the freezer. He does seem particularly passionate about his new brand of fishcakes: “Have you tried making them from scratch? They’re a bit of a faff. You’ve got to flour ‘em, egg ‘em, breadcrumb ‘em, and then there are four things dirty.

“So if you can buy a good quality one, that’s economical, delicious and saves you half an hour… well, pukka.”

Ah, yes, some things never change.

Here are two cool recipes to try…

Spicy salmon burgers from frozen

(Serves 4)

454g frozen salmon, cooked & flaked

Half red chilli, deseeded & chopped finely

4 spring onions, chopped

1/2 pepper, chopped finely

Rind and juice of half a lemon

1tbsp chopped dill or flat leaf parsley or 1tsp dried mixed herbs

Breadcrumbs

1 egg, beaten

2tbsp olive oil

4 burger buns from frozen

Lettuce to garnish

4tbsp tartare sauce to serve

Mix the ingredients for the burgers together in a large bowl. With lightly floured hands, form handfuls of the mixture into burger shapes.

Heat the oil in a large non-stick frying pan and fry the burgers over a medium heat for 10 minutes, turning carefully halfway through cooking time.

Serve on lightly toasted buns with lettuce and tartare sauce.

• For more information on frozen food, visit the British Frozen Food Federation at www.bfff.co.uk

Chilli & Lime pan-fried prawns with noodles

(Serves 4)

60g Benecol Buttery Taste Spread

6 spring onions, chopped

1 red pepper, deseeded and sliced

110g beansprouts

1 red chilli, deseeded and diced

2 pak choi, leaves divided

350g frozen raw tiger prawns, defrosted and peeled

Finely grated zest and juice of 1 lime

½tsp sugar

2tbsp light soy sauce

3 x 150g packs thick noodles to serve

2tbsp coriander leaves

Melt the Benecol Buttery Taste Spread in a wok or large frying pan and heat until hot. Add the spring onions, pepper and beansprouts and stir-fry for three to four minutes until softened. Add the chilli, pak choi and prawns and continue stir-frying for two to three minutes until the prawns have turned pink.

Mix together the lime zest, juice and soy sauce with the sugar and cook for one minute until everything is hot.

Cook the noodles according to the pack instructions, drain well and divide between four serving dishes. Top with the stir-fry and garnish with the coriander leaves.

• For more Benecol recipes visit www.benecol.co.uk

• Please note language in par 23.