Oh, the shame. Last night I broke one of my cardinal rules by poking my busybody nose into the wine choice of the people sitting at the next-door table. No sooner had I opened my big mouth than I wished I had not.

We were drinking a competitively-priced Barbera d’Asti AA Trinchero 2003 (£26.50 a bottle) and I had been quite seduced by its bramble and crunchy red cherry fruits and the perky acidity that I associate with Barbera and all good Italian food wines.

Clearly I had been overly seduced because I was only half listening to the sister and was, instead, watching the gentleman to my left study the wine list as though he had been given an exam paper. I could see his lips move as he read the descriptions to himself and I felt positively maternal when he dropped his head into his left hand and began scratching his forehead with his glasses.

I have never seen a wine list snapped shut so fast as when his guest arrived. Clearly, he was not about to share whatever knowledge he had garnered in the last five minutes.

“What shall we have . . . I love Tuscan wines.” The list was reopened and there then followed a conversation that sort of went like this. “Ah yes,” said Mr Studious “but this one has been aged in oak and so is bound to be a classier wine”.

“But what a price!” exclaimed the newly arrived.

I did not know who I thought I was rescuing but I felt bad for the guy who had just rocked up; he was being given rubbish advice by a bloke whose wine knowledge stretched to the snippets he had read only five minutes ago.

And equally, it seemed that Mr Studious was just desperate to make a good impression.

I suggested they try mine. They liked it but they did not like the acidity. Mmm . . . I cast my eyes over the Italian list, listened to their concerns about price and made two carefully selected suggestions.

They were polite and gracious and I am enormously grateful because they had obviously decided I was some sort of nutcase and were two men perfectly capable of making their own minds up. Quite right too!

So, they opted for I Vigneri Salvo Foti Etna Rosso 2008 (£51.45! a bottle) . . . a wine I have always found delicious but quite unique and arguably sharper than our Barbera. They both took a healthy glug, turned to me and, in unison, announced it, “delicious”. So, what do I know? Well, I know that Terroirs in London (www.terroirswinebar.com) remains one of my favourite pre-theatre places to wine and dine in London.

The food is unashamedly French and the wine list is exciting, innovative and not short on choice.

Clearly, if you get a chance to go you will have lots of people itching to help you make a good wine choice, but I can definitely recommend the Barbera and — if you are in the mood for some sparkling with pud, have a glass of the lightly sweet, utterly delicious Moscato d’Asti from Vittoria Bera 2009 (£6.25 a glass).