Combine vodka, lemon juice, Bacanha lychee syrup, star-anise bitters, petal-and-amaranth-blossom infusion and egg white in cocktail shaker and shake five times. Add ice cubes and shake again until shaker feels cold.
Strain through fine-mesh sieve. Pour into glass and garnish with rose petals and amaranth sprig.
Notes
To make the petal-and-amaranth-blossom infusion, place 2 big tbsp of dried rose petals and 1 tbsp of amaranth into ½ L of boiling water. Let the flavours infuse until the water has cooled, then strain the liquid.