What is a Mexican martini cocktail?

A signature cocktail of Austin, Texas, the Mexican Martini Cocktail  is a wonderful juxtaposition of salty and sour. It’s made with the same ingredients as a margarita, but instead of being served on the rocks, it’s shaken with ice, poured into a martini cocktail glass and garnished with olives. Some bartenders even add olive brine to the shaker.