50m/2fl oz Livener
10ml/2 barspoons Monin triple sec
25ml/1fl oz lime juice
Salt or Tajin seasoning
Swipe a slice of lime around the rim of your serving glass and coat the slightly damp rim with salt or Tajin by putting some on a plate and placing the rim of the glass in it.
Combine the other ingredients in a cocktail shaker filled with ice and shake hard until the whole shaker is icy, then strain into the salt or Tajin rimmed glass and garnish with a slice of lime.