Cocktail of the week: The Tinkerbell Venetian Kiss, was the most straightforward in looks and substance: Prosecco with an Aperol, peach and grape foam. Others, such as Purl No 1 cup, a Pimms-based cocktail complete with its own patch of turf and Smoky & the Bandit, which was accompanied by smoked salmon, would have been a talking point - if any of the assembled hens had paused for breath. The most delicious of all in my opinion was Cubra Libre del Pobre, a rum and coke jazzed up with a red wine ice lolly and fizzy grapes. Unless you fancy yourself as a molecular mixologist and own a dry ice machine, I'd have thought these cocktails would be too much of a faff to make at home but Purl's owner Bryan Pietersen disagrees. He recommends serving his favourite cocktail, the Tinkerbell, as an alternative to pudding. "It's like a fresh dessert, really good after dinner," he says. It sounds innocent but it's not. The Tinkerbell is a rum-based drink featuring a line-up of obscure ingredients such as banana liquor and an edible disc to be folded into a butterfly. It involves making a mango foam and crispy mint leaves. Read the recipe below and get making your own Tinkerbell. You'll appreciate every sip. The Tinkerbell, by Purl's head barman Emanuele Genovese Serves 1 400ml mango juice 50 ml sugar 100ml egg white 45 ml Diplomatico Reserva rum 15 ml banana liquor 10 ml fresh lime juice 3 drops liquorice bitter 3 or 4 Mint leaves A dash of walnut oil An edible disc (you can buy them at Molecular Recipes) A cream whipper (try Cream Supplies) Shaker and strainer Cocktail glass First make the crispy mint. Choose the most attractive mint leaves you can, lay on cling film, brush with walnut oil and microwave for 2 minutes. For the mango foam, add the mango juice, sugar and the egg white to the cream whipper and charge twice. Then shake the Diplomatico Reserva, banana liquor and lime together, double strain in a cocktail glass and pour over the mango foam, and crispy mint. Then decorate with the edible disc, folded in half to resemble a butterfly. Purl, 50-54 Blandford St London W1U 7HX, 020 7935 0835