Rinse lemon verbena leaves and lavender flowers and remove the stalk from the lavender up to the base of the flowers. Rinse the lemon and cut off 1-2 slices (if you like, you can use more). Put everything in a mason jar, add the rock candy and pour the grain over it.
Let it rest for approx. 4-6 weeks.
Strain and fill into bottles. Possibly let it rest for a while if it has not yet passed the tasting.