Hidden within the quiet streets of London’s St. James neighborhood, the bar at the Dukes Hotel has, for the past 35 years, been home to a Martini so unique that it’s become a modern classic in its own right. Prepared tableside, on the same rosewood trolley that’s been serving the bar for more than a century, the Dukes’ Martini epitomizes a blatantly old-school version of the iconic cocktail: served bracingly cold, in a large, V-shaped glass, with very little vermouth.

Though the bar, which was a favorite of James Bond author Ian Fleming, has always served Martinis, they didn’t begin offering the current version until the mid-1980s, when Dukes was managed by cocktail legend Salvatore Calabrese. It was Calabrese who created the “direct Martini” method, which calls on already-frozen gin or vodka, and eliminates the step of stirring with ice all together.

Served in a glass prepared with just a thin wash of vermouth dispensed from a bitters bottle, Calabrese’s original Dukes’ Martini hit the map when it became an instant favorite of journalist (and bar regular), Stanton Delaplane, who described it, in an article for the San Francisco Chronicle, as the “best Martini in England.”

After Calabrese left Dukes, the tradition of the bar’s Martini was carried on by fellow Italian bartender, Gilberto Preti, and most recently by Alessandro Palazzi, who’s managed the bar since 2007, and has given the drink his own subtle twists.

Palazzi begins by giving the chilled glass a rinse of English dry vermouth—made with a base of English wine, produced by the Sacred distillery in North London and made in collaboration with Palazzi himself—which he then tosses over his shoulder and onto the carpet. Next comes the gin, so cold that its consistency is almost syrup-like. Though Alessandro will make a Martini with any of the 15 different gins that Dukes keeps in the freezer (and, in some cases, even vodka), he favors those made in the classic, juniper-forward London Dry style.

But the final, key ingredient in the Martini, says Palazzi, is a twist of an organic, unwaxed lemon from the Amalfi coast, which he started using shortly after taking over the bar. The fruit’s large size allows for more essential oils to hit the glass when expressed over top of the finished cocktail—an important consideration given the volume of the drink. Rumored to amount to a staggering six ounces of spirit, the Martini is so potent that it comes with a two-drink maximum.

“[It’s] £19.50, but you get five shots of alcohol,” says Palazzi, who encourages guests to linger over their cocktails for as long as they’re comfortable, rather than rush. “If you have two, it will be ten shots. We have to be responsible.”

As for Palazzi himself? After an evening of making some of the world’s most sought-after Martinis, “I prefer a Negroni or Manhattan,” he says.