Few cocktails have reshaped the modern bar scene as quietly and as profoundly as the Tommy's Margarita. Born not in a sleek cocktail lounge but in a humble Mexican restaurant in San Francisco, this three-ingredient masterpiece has become one of the most celebrated drinks of the last three decades.

The Tommy's Margarita was created in 1990 by Julio Bermejo, the son of Tommy and Elmy Bermejo, founders of Tommy's Mexican Restaurant in the Outer Richmond neighbourhood of San Francisco. The restaurant, which opened in 1965, had long been a neighbourhood institution — but it was Julio's obsession with agave spirits that would change cocktail history.

Frustrated with the artificial sweeteners and cheap mixers that dominated Margarita culture at the time, Julio set out to create a version that honoured the integrity of the tequila itself. His solution was elegant in its simplicity: replace the traditional orange liqueur (Cointreau or Triple Sec) with agave nectar, and use only 100% agave tequila, never a mixto.