Add wine, tequila, blue curaçao, creme de cassis, salt, agave and lime juice to the shaker and shake until cold.
Pour into glass and top with lime soda.
Add frozen berries to liquid and serve.
Scientist's Notes
This recipe creates a sweet, deep purple-coloured margarita. I was inspired by my pet peacock, Pablo, for this one, but if the colour isn't important you can use the usual Triple Sec, and any berry flavoured liqueur.