Imagine the wails if the delicatessens started selling kelims; if the corner shop started stocking a line in recycled, hand-blown glassware; if you could buy hand-made, cast-iron, hessian covered sofas at Asda. It would be like straying on to God's territory: warnings of unleashing monsters on to the world would abound in the consumer magazines, pressure groups would rattle out dire warnings about job losses, the Conrans would give interviews showing that the quality would be impaired. Food shops sell food; design shops sell design: that is how it should be.

Except that the design shops don't really see it that way. Every good decorative emporium now has a department - or at the very least a chrome- plated five-tier shelf - stacked with dinky food to grace your kitchen. Not least about these are the olive products. Perhaps this is related to the peculiar British fear of things Mediterranean - it's not so long, after all, since olive oil was something you bought in tiny bottles from the chemist to clear your earwax - but things you would expect to find in any old Italian village shop turn up here as luxury designer goods at luxury designer prices. It is in these outlets that you will find your unsullied olive oil with a twig or tarragon or bunch of chilli peppers bobbing around the bottom of it and a glorious Tuscan sunset on the label.

Safeway may have caught up with pesto and dried tomatoes, but they have a long way to go before they stock giant jars of marinaded olives artfully striped in layers with orange, garlic, silverskin, onions and spices.

The thing about these beautiful foodstuffs, though, is this: who actually buys them? We must all have stood in front of the displays, mouths watering, fantasising about spending upwards of pounds 30 on snacks, but how many of us have reached out and popped one into our baskets?

My theory is that they are bought by that particular urban brand of person who never cooks, but who likes to keep a decorative kitchen nonetheless. The type of people who have other people in for drinks before going out to a restaurant.

These people, who nurture a secret longing to have their house appear in Country Living, also have bunches of dried herbs and copper pans hanging on old laundry racks suspended from the kitchen ceiling. "Look!" proclaims their interior decor. "I am a busy person and a wealthy one, but really I long for the simple things in life: fresh fruit shared with friends, a bowl of pasta with pine kernels, the smell of new-baked bread..."

So who eats them? Well, no one, at least at the outset. These are for decoration as much as for consumption. Once the Umbrian scene on the label has been obscured by grease from the gas ring and splashes from the espresso machine, then perhaps the bottle will be replaced in the next-to-cooker display rack, opened and consigned to the cupboard for salad-making. But it's rare that these beauties get eaten at their best, when they're still fresh. As for the marinading jars, they'll sit casually on a side somewhere until the next party, when the local dipso spots them, cries "Ah, olives!" and pops the seal on the top.

Of course, they also make great non-contentious presents. Presents to give to the unexpected guest that no one warned you about. Gifts to take to partners' mothers. Gifts that say that you're a person of good taste and the recipient is a person of culinary discernment. This is a good time of year for sales of tarty oils, as it is a good time for posh soap. After all, both are better than a pair of socks.

Serena Mackesy