Cocktail Recept: Paris opera

A Paris opera cocktail contains the following ingredients:

• 3 cl. Blue Curacao 
• 2 cl. Rum 
• 3 cl. Grapefruit juice
• 1 pair Ice Cubes

Put some ice cubes in a shaker.
Add the remaining ingredients.
Then shake the mix vigorously.
Pour the mixture through a strainer into a cocktail glass.
Serve the cocktail immediately.