Food that is simmered in a covered pan with a small amount of Vichy water, butter and sugar (no salt), then drained and sprinkled with minced parsley for flavour, texture and colour. The food comes out glazed.
Purists insist that Vichy water makes all the difference; that it has a slight calcium edge that comes through, and that keenly-edged tastebuds (i.e. non-smokers and drinkers, perhaps) will taste the difference if you just glug tap water in instead.
The food writer Jane Grigson pooh-poohed the idea that anyone could taste the difference; those caught in the middle and unsure (e.g. the smokers in the crowd) venture that a pinch of baking soda in the tap water might amend for the lack of authentic Vichy water.