Pour Blue Curaçao syrup on a plate. Put sugar on a second plate. Dip 4 glasses with the rim of the glass first in syrup, then in sugar. Put peach nectar, whipped cream, cassis syrup, chanterelle and ice cubes into a shaker and shake vigorously for about 20 seconds.
Then distribute to 4 glasses through a bar strainer. Hold a drinking straw in the Blue Curaçao syrup bottle and wait until it is full. Close the top with your finger so that the syrup does not leak.
Run down the inner edge of the glass. Repeat this procedure several times so that the glass is streaked with several blue stripes. Serve garnished with mint.