There are parts of London that I know like the back of my hand. Hanover Square in salubrious Mayfair is one. I know every paving stone. I’m on first name terms with every grand oak that lines its garden. You see, I worked here for over a decade when I was a wine buyer. Wine-Journal was essentially born here. Perhaps I should use the past tense, because this Regency square is unrecognizable since we parted ways in 2006, entire buildings demolished or disemboweled to make way for the new Crossrail line. The only features extant since my days here are the trees and the waifs going in and out of the Vogue office. My old office in Mimosa House is now an art gallery and what was a branch of “Thai Square” has recently emerged as “Stem”. Stem is the third restaurant opening for Mark Jarvis following the much-lauded “Anglo” in Clerkenwell and “Neo Bistro” (also in Mayfair). On this showing, just days after its soft launch, “Stem” might well be the best.