Django Reinhardt

Muddle the orange slices gently in a shaker using a muddler or wooden spoon.

Add the dry vermouth, freshly squeezed lemon juice, and simple syrup to the shaker.

Fill the shaker with ice cubes and shake vigorously until the mixture is well-chilled.

Fine-strain the mixture into an Old Fashioned glass filled with fresh ice.

Garnish as desired.