Emerald

Chill a cocktail coupe by filling it with ice and setting it aside.

In a mixing glass, combine the Irish whiskey, sweet vermouth, and a few dashes of orange bitters.

Add ice to the mixing glass and stir the mixture until well chilled.

Discard the ice from the cocktail coupe and strain the mixture into the chilled glass.

Garnish with an optional orange twist for an aromatic finish.