Western sour

 2 oz Bourbon (or rye)
1 oz white grapefruit juice
0.5 oz fresh lime juice
0.5 oz falernum
0.25 oz sugarcane syrup

Shake well with ice cubes and por unstrained into a double old fashioned glass.
As i suspected, white grapefruit juice and kalamansi limes like each other and plays together very well..and here the two together is da bomb! this drink is so tasty!

I think i need to go and get me a kalamansi plant so i can have fresh kalamansi limes and make these  drinks all summer!