Jan Moir Are You Ready To Order

We can't travel anywhere without arguing. Is that a sign of getting older, or is it something else? Is it me, or is it him? It's him, of course. It has to be. As he says himself: ''Sorry, I keep forgetting you're perfect.'' Ten years ago, we would do anything to be together. Who cared if the flight was delayed or the hotel overbooked. There was always coffee and each other, plus the prospect of somewhere different and new things to eat.

Remember, S, that rainy weekend in northern Spain, when you ate so much shellfish at lunch that all the cooks came out to stare? Getting you back to the hotel was like pushing a broken piano up a hill. Then I had to spend the next day fetching remedies from various chemists as you lay on the bed, heaving and groaning. Back then, I didn't even mind. I thought it was quite funny. Now I might get terse and say: listen, stupid, is there any possibility that your stomach won't explode on day one?

But I am trying to be a better person. Really I am. At Bologna airport there was a frizzy-haired woman in poultice-coloured linens, stomping ahead of her husband in utility sandals that looked like they had seen a few miles. Her mouth was set like a zip and her face was flushed crimson, verging on the full Krakatoa. ''Please, just co-operate,'' he was begging, bobbing along in her wake like a doomed cork. It gave me a portentous shudder. I hope I never get like that, I told S. At this, his old oyster eyes bulged and I knew that he was thinking: you already are, you monster. So now I'm trying to be mellow, to quell my inner shrew.

A few days later, we miss the motorway turn-off for Senigallia three times and I do not say a word. ''We'll get there in the end,'' says S cheerfully, adhering to his lifelong habit of buying road maps but never looking at them. Isn't that adorable? My, this vodka and champagne cocktail is delicious. Perhaps I'll have another one.

Senigallia is a pleasant, modest resort town in Marche, popular with Italian families enjoying the Spiaggia di Velluto - the velvet beach - that runs for 13 kilometres along this blue-flag coast. The town also has a reputation as a gourmet centre, boasting two of the top 20 restaurants in Italy, plus another three or four that aren't far behind. The most famous, La Madonnina del Pescatore, has three Michelin stars and a glittering reputation, but catching up fast is the incredible Uliassi, set right on the beach in the centre of town.

Run by chef Mauro Uliassi and his sister Catia, it is as far removed from the traditional Italian seaside restaurant as you could imagine. The interior of the spacious, modern building is resolutely hip, with stylish Ron Arad chairs, glittering nautical mosaics, a giant, glossy palm leaf in a vase on each table plus dazzling views of the clear, bright sea and a forest of jolly sun umbrellas spiked across the sand. There is an elegant white wooden terrace, edged with purple flowers, that wouldn't look out of place in Sag Harbour, and charming, unpretentious staff who do their best to explain the complicated selection of forward-thinking menus.

As well as the à la carte, Uliassi has a multi-course, completely-raw fish menu and various tasting menus featuring baccalà and stockfish. In the end, we surrender to the Menu Sorpresa, designed to show off the talents and techniques of the chef and his 16-strong kitchen brigade over a long, languid lunch. On a day when sultry heat can turn even the most robust appetite limpid, when freshness and flavour seem more important than ever, it turns out to be the perfect thing to do.

The meal kicks off with a loacker di fegato grasso e pralina di nocciole, Uliassi's signature culinary joke. The savoury titbit looks exactly like an everyday teatime wafer biscuit, except it is filled with layers of foie gras and a Nutella-like confection, then sprinkled with a few grains of salt. Somehow managing to be crispy, rich, sweet and restrained at the same time, it's one of the most delicious canapés I've ever had. S throws his down his throat like a chimp with a peanut, then looks baffled when I ask him if he enjoyed the joke. What a dreamy guy.

Meanwhile, a cavalcade of beautiful, amazing dishes follow, including a "fettuccine" of cuttlefish ribbons; slices of raw gurnard speckled with poppy seeds and pea shoots; prawns served "Japanese style", dusted with some kind of space-age lemon powder; plus a little salad of melon, cucumber and courgette flowers that is elfin in its whispery fragility.

A dish of fresh squid and curls of sole is dressed so beautifully with herbs, vegetables and sweet baby asparagus that it looks like a painting, while red mullet comes with cubes of foie gras and melon; then something they call "frogfish" smoked with pink grapefruit and cress. This is the only shaky note, as it tastes like something dredged from the deep with a nasty 60-a-day habit.

Next, we are each given a sealed Kilner jar containing a selection of cooked shellfish, a cocktail stick speared with fat cloves of garlic and a brodo scented with aromatics such as lemon grass, celery and onion. When you first pop open the lid and inhale, the seaside tang is incredible, and what follows is like eating your own perfectly cooked rock pool.

Other outstanding dishes include inky strigolo pasta served with nutty, young squid and clams perfumed with basil; and immaculate, milky suckling pig garnished with orange zest, fennel fronds and a shard of golden crackling. A gorgonzola ice with a side-saddle of celery granita shakes your taste buds back into shape, ready for a whippy mousse studded with pieces of fresh ginger piled between two biscuits, over which is poured a pot of chilled lemon tea.

The Menu Sorpresa is a bravura meal, a delicious piece of showing off that makes one keenly aware of the unimpeachable provenance of the ingredients and of the kitchen's deft way with them. Uliassi is not one of those chefs, like some in Britain, who muck about with gastronomy just to make a lurid and flashy point; his understanding of how food works is innate, fresh and deeply enjoyable. Clearly taking great pride in what he does, he serves food to make you fall in love again. Isn't that right, my darling S?

• Uliassi, Banchina di Levante, 6, Senigallia, Le Marche, Italy (00 39 071 65463). Menu Sorpresa for two, excluding drinks and service, £120.