The great White makes an urban appearance (+recipe)

Shop-bought stock is one of those sneaky products that finds its way into the shopping trolley despite the guilt of knowing it wouldn't have been that hard to boil the bones from last week's roast. It's not the sort of purchase a former Le Gavroche chef would usually encourage - especially one with the skills to earn three Michelin Stars and the attitude to land a lead role on Hell's Kitchen.

But Marco Pierre White is not afraid to fess up. He doesn't bat an eyelid when he tells me that the famous London Le Gavroche churns through stock concentrate in bulk containers. There, he says, it's added to just about everything, and apparently that's nothing he's ashamed of.

Pierre White worked at Le Gavroche when its kitchen was run by the famous Roux brothers, who were at the top of their game despite having no formal training. Pierre White says they were not compromised by the ingredient snobbery emerging in many of today's chefs.

"It's not about cutting corners, it's about flavour. Great technical ability is what you need to create flavour. The Roux brothers didn't have that, at least not in a classical sense."

That's not to say they were turning out dishes made with flavour sachets or two-minute noodles.

"It's how you use something. I use stock concentrate as a seasoning. Some people will call that cheating or taking a short cut, but if that gives the best flavour, why wouldn't I use it?"

When Pierre White cooks for friends, one of his favourite creations is boiled sweet potato blitzed in the food processor with a 28g stock pot and a sprinkle of pepper. He serves it with braised beef or hearty stews and says it makes them shine. Children like it too because, as he puts it, the mixture is soft and golden and that's what children are drawn to.

Pierre White is also remarkably humble about his taste in meat. His advice is to forget expensive steaks and fillets, instead going for the shin and shoulder - two of the cheapest cuts.

"The most flavour is always closest to the bone," he says. "Meat cooked in a pot tends to be tastier than meat cooked in the pan."

When it comes to stocks, stews and risottos, he says many home cooks dilute these dishes with stocks that are little more than stained water. Home-made stock is tricky to get right.

"The reason why people don't make great stocks at home is firstly because they don't have a big enough pot; secondly, because they don't have enough carcasses to make it properly and thirdly because it costs a fortune to have all the seasoning to create a decent flavour."

His advice is to add two small pots of stock concentrate in with the bones and vegetable scraps, before boiling in a large pan with plenty of water.

For a quick stock, Continental stock pots, which are effectively a jelly concentrate, can be diluted to make eight litres of regular stock. It works out slightly cheaper than buying the bigger containers of stock.

Pierre White says another way to achieve greater flavour is to skip the stock entirely, replacing it with freshly squeezed vegetable juice. A stock pot can be added later to intensify the flavours that come off the meat or vegetables as they cook.

Marco's pumpkin soup
Carrot juice is used instead of stock, with a container of stock concentrate to give depth.
1 Dice 2kg of pumpkin soup into 3cm squares and cook in a pan splashed with olive oil for 10 minutes, stirring every so often.

2 Add 1.2L of freshly squeezed carrot juice and two Continental stock pots. Bring to the boil, and then lower to a simmer for eight minutes.

3 Add 100ml of fresh cream and cook for another two minutes. Season with salt and pepper.