For discerning summer chefs - who know their filet from their flank - there has only been one BBQ brand of choice in recent years. The Big Green Egg, the dimpled, racing green outdoor cooker that can turn out perfectly flamed steaks, burgers and even roasts, has dominated the middle class market for nearly a decade. Famous faces including David Beckham, Meghan Markle and Liz Hurley have all grilled up a storm next to the distinctive egg-shaped oven, which retails from around £1,500 and is made from NASA-grade ceramics.However, there's a hot new BBQ on the block - and her name is Bertha.The British-designed charcoal oven has been a fixture in professional kitchens for decades but as big-spending serious home cooks try and replicate what they eat in Michelin-starred restaurants, it's now set to appear in back gardens too. Bertha, a £4,500 charcoal oven in a range of trendy colours, is now being stocked at John Lewis. The al fresco cooking appliance was designed for professional kitchens but looks set to be popular with serious home cooks - who have deep pockets The Lancaster-based company says the charcoal oven promises 'faster cooking and deeper flavour' - with the ability to grill, roast, bake and smoke with natural charcoal in a single enclosed ovenJohn Lewis revealed earlier this month that it's selling the al fresco 'high performance' cooker, which comes in eight punchy colours including 'orange', 'raspberry' and 'aubergine'. While the appliance might have a down-to-earth English name, its price tag is anything but. The Bertha Original freestanding oven, which looks remarkably like the kind of safe you might find in a heist movie, retails at £4,500, with a smaller table top version available for £1,000 less.The brand recommends Sumi Bincho charcoal, which costs a princely £28 for a 10kg box. What does £4,500 buy you? The ability to grill, roast, bake and smoke with natural charcoal in a single enclosed tiered oven. The company says: 'With even heat and precise control, Bertha delivers consistent results, faster cooking, and deeper flavour.' The Big Green Egg, designed in the US in 1974, has been the BBQ of choice for the rich and famous in recent years, with David Beckham, the Duchess of Sussex and Liz Hurley all fansThe Bertha has already amassed some celebrity fans. Food critic and TV personality Jay Rayner gushes on the company's website: 'I’ve experienced what she can do, and what she can do is very pleasing indeed… Who wouldn’t want a serious chunk of bespoke wood fired oven?'And high profile chef Mark Blatchford is also a fan of the pro oven, saying: 'Unlike a traditional oven with a fixed heat source you can manipulate and move the charcoal/wood/peat heat and with fantastic results. I’d never be without one.' The arrival of Bertha could see the nation's well-heeled outdoor cooks swapping out their Big Green Eggs, which have been the posh BBQ of choice for nearly a decade. While Big Green Egg was founded in 1974 in Atlanta by Ed Fisher, the Bertha was established in 2013 on British shores - the company has its HQ in Lancaster.In 2018, David Beckham posted a picture of himself trying to cook a whole fish stuffed with lemons - which was too large for the grill - in his Big Green Egg.On Instagram this week, John Lewis shared a video of the Bertha cooking up a stormHe captioned the image: ‘Maybe I should catch a smaller one next time. Or get a bigger Green Egg.’Kirstie Allsopp, Liz Hurley and Meghan Markle also shared their love of the Green Egg that summer, with the Duchess of Sussex saying at the time that her favourite meal was a ‘lunch of fish tacos and albarino cooked in my backyard on my ceramic grill (the Big Green Egg)’.Serious home cooks are increasingly spending on professional kitchen equipment, with coffee machines, juicers and even deli-style meat slicers appearing in UK homes. Pro chef Homam Ayaso says social media has transformed culinary aspirations when we're cooking at home.'There's been a real rise in seeing such equipment in homes. I think the main reason is probably social media.'Where once people thought such appliances were too professional and expensive, they realise that they're now actually more accessible.'People want fine dining at home, they want restaurant quality, cuts and approaches.'