From the post: Encore! (More party recipes!)

Makes 1 cocktail

6 ounces champagne
1/2 ounce crème de cassis

Pour the champagne into a flute. Allow it to settle for a moment. Gently pour the cassis down the inside of the glass through the champagne. The Kir should have a layer of cassis at the bottom. Garnish with a lemon twist or with a blackberry if desired.