Put the cinnamon, cloves, star anise, cardamom and peppercorns in a dry frying pan, and toast for 5 mins, or until the spices are just fragrant. Remove from the heat and leave to cool.

Tip all the toasted spices into a medium jar and pour over the gin. Seal and chill for 48 hrs to infuse.

Strain the infused gin through a fine mesh sieve, and fill four to eight glasses with ice. To mix the cocktail, tip 25ml each infused gin, vermouth and Campari into the glasses, then garnish with orange slices and bay. Any leftover infused gin will keep, sealed in a cool, dry place for up to two months.