Add gin, Campari, sweet vermouth and one strip of orange zest to a mixing glass. Fill glass with ice and stir for 15 seconds.

Serve on the rocks: Strain the mixture into rocks glass containing large ice cubes and garnish with remaining orange zest.

Serve frozen: Blend at high speed until smooth and transfer to a frosted rocks glass. Garnish with orange wheels and, if you like, a splash of Prosecco.