The very definition of an aperitif: light and mouthwateringly bittersweet. The American writer Charles H Baker came across this in Borneo, after a dicey afternoon adrift in a boat. Amer Picon is an old orange liqueur that’s having a bit of a renaissance. Serves one.

30ml gin (I use Miller’s Westbourne)
25ml extra-dry vermouth (Gancia, for preference)
10ml orange curaçao liqueur
5 dashes Amer Picon
1 dash Angostura bitters

Stir everything in a mixing glass or jug for 10 seconds, strain and pour into a glass over ice. Garnish with a slice of pineapple and a mint sprig.

• Rebecca Seal, drinks historian, Sheraton Grand London Park Lane