See also: Chartreuse, The Liqueur
A chartreuse was originally a term referring to a preparation of vegetables (in aspic) layered in alternating colors in a mold, cooked in a bain marie, turned out and served hot.
It takes it's name from the Carthusian order of monks (vegetarians) who probably created it. Now a chartreuse may also contain minced poultry or meat.
There is also a story (which has the ring of truth) that on days that meat was forbidden, it would be hidden in the center of the chartreuse, enabling the monks to indulge themselves with the forbidden food.