It is a specialty of the village called “Tourrettes sur Loup” in the south of France.
To make it, fresh violet petals are covered with boiling water, and let stand and infuse for a day.
Then it is strained to get the petals out, which are discarded. The water will be bluish.
For every cup (8 oz / 250ml) of the coloured water, you add 2 cups (1 pound / 250g) of sugar and the juice from half a lemon. You put it in a pot, bring to a boil, lower to a simmer and simmer for a few minutes until the sugar is dissolved and slightly thickened.
Then, you remove it from the heat, pour into sterilized jars, and seal and store in refrigerator.
Violet Syrup can be used in beverages or as a topping.