Add the mint leaves, lime juice, halved kumquats and agave in a cocktail shaker and muddle until the kumquats break down and start to release their juices.

Fill the shaker with ice, add the tequila, cover and shake for about 30 seconds or until the shaker is nice and cold.

Pour the cocktail between two collins or old fashioned glasses. If necessary add more ice and if desired top off with club soda.

Garnish with mint, a slice of lime and half a kumquat.