With another weekend of scorching temperatures on the cards, people all over the UK are pulling out their barbecues. Top chef Jackson Boxer, the brains behind hip restaurants Brunswick House and Orasay, says many people will be making a couple of crucial mistakes.

Adding ketchup to a burger “utterly vandalises” the flavour, he says, and in particular he singles out the convenient pre-sliced packs of cheese that may of us will be buying as part of our BBQ prep.

You should never use cheddar on a burger, he tells The Times: “It mostly tastes of emulsified butter fats. Personally I think good beef should already taste of this: rich, buttery, almost cheesy."

Instead, he recommends Gorgonzola, the famed Italian cousin of Stilton, with a soft, crumbly texture and a flavour that can be particularly sharp and pungent in more aged varieties.

"It's much more rewarding to add a cheese that provides a counterpoint to the beef and allows its particular qualities to come to the fore,” Jackson says. “I think that young gorgonzola, with its high sweetness and subtle piquancy, does a much more exciting job of this."

He adds that while gherkins have their place, it’s most definitely not sliced up and placed on top of the burger itself. You shovel only put a gherkin "On the side, where I can see it.”

He’s similarly dismissive of adding salad to the mix: "Generally speaking I just want the bun, the cheese-blanketed patty and nothing else," he says.

The only exception Jackson would be willing to make, he says a slice of very good tomato or possibly onion.

While supermarket shelves are these days heaving with plant-based burger alternatives, Jackon’s not really convince day any of them: "I have had exactly one good vegetarian burger in my life, which is the one Brooks makes at Superiority Burger in New York," he says.

"I believe it's chickpeas, quinoa, alliums and spices, but I've never engaged too seriously in trying to replicate it.”

He explains that. In his opinion there’s no vegan burger out there that tastes as good as falafel, which he describes as “unimprovable.”

Jackson is a big fan of unfussy food. When he started Brunswick House, which is now an elegant restaurant and cocktail bar featuring antique furnishings and offering a menu of remarkably inventive dishes, it was little more than a sandwich bar.

It was about a year until we got our alcohol licence,” he told men’s lifestyle site SL Man. “Once that happened, I did a simple evening menu because I only had a small oven and a hob to work with – homemade sausages and lentils, terrine and toast, grilled sardines on toast and… something else on toast! ‘

“I think that was the full extent of the menu in those days,” he recalls, “and we charged what we could.”