Kir is a popular French cocktail made with a measure of crème de cassis topped up with white wine. In France it is usually drunk as an apéritif before a meal or snack. There are also many variations of the kir, the most notable being the kir royale, which uses Champagne or Prosecco. There are other versions that use cider or different liqueurs as well.
Add the crème de cassis to the bottom of the glass, then top up with wine.