The classic one Margarita recipe contains tequila, orange liqueur and freshly squeezed limejuice, but as with so many other classics, bartenders and cocktail enthusiasts find ways to adapt the recipe to suit the time and the crowd.
This is how the recipe for the modern classic Tommy's Margarita originated, which was created by Julio Bermejo in the early 90s at Tommy's Mexican Restaurant in San Francisco. It is now served all over the world, as countless restaurants and bartenders have copied the idea from Bermejo, to achieve a lighter and fresher version of a Margarita.
Source: Tommy's Margarita wikipedia