Cocktail of the week: Bibi’s salted old fashioned | The good mixer

At the restaurant, we make this with kithul syrup (or treacle), a Sri Lankan ingredient we’ve championed on our cocktail menu ever since we opened. The best ones are made by refining palm sap over a charcoal flame, which imbues them with a delicate, smoky flavour – you can buy them online, and if you do get hold of some, make the base for this drink by dissolving 1g salt in 100g water, then stir in the syrup. Failing that, we’ve adapted the recipe for home use by making a palm sugar syrup instead. Either way, pair the syrup with wheated bourbon, a style known for its fruity notes and banana esters.

Salted old fashioned

Serves 1

For the syrup
1½g salt
200g palm sugar, grated

For the drink
­10ml salted palm sugar syrup (see above and method)
50ml good wheated bourbon – we use Makers Mark
3 dashes Angostura bitters

To make the syrup, put the salt in a jug filled with 100ml just-boiled water, stir in the palm sugar until it dissolves, leave to cool, then chill.

To make the drink, measure all the ingredients into a mixing glass, then fill with ice and give it a good stir to chill and dilute the liquids. Strain into a whiskey tumbler, fill with fresh ice to taste, and serve.

• Chet Sharma and Guy Mazuch, Bibi, London W1