"Pour one jigger absinthe into a Champagne glass. Add iced Champagne until it attains the proper opalescent milkiness. Drink three to five of these slowly."
First a word of warning; unless you are a professional drinker three to five of these even if you have them slowly will leave you at least more than a little buzzed. While the exact alcohol content of Absinthe varies by brand, it's universally rather strong, generally hitting around 140 proof or so. Combine this with the champagne and you are going to get hammered if you throw these down too quickly; and they can go down quickly as it's a rather smooth and refreshing drink.
So it's a rather simple cocktail to make, and the big question is to what absinthe or champagne to use. In regards to the absinthe, I am in no way a connoisseur, but there are some rather big differences out there in what's available. In the US the brands I've been happy with have been Vieux Carré, Mephisto, and Pernod. I actually like Mephisto in this cocktail because it's a little lighter on the anise flavor and find it creates a little lighter drink, which I think is nice.
As for champagne- I am certainly not a purist here. In fact I think a lot of people get caught up with labels and where things are made. As much as it benefits some to really play this up, the reality is that you can get some really drinkable stuff fairly cheaply. Since the effervescence will get eaten up shortly in the mixture, there's no need to waste really expensive champagne here. A good sparkling wine or Prosecco is just fine. More important will be balancing the flavors of the chosen sparkling with the chosen absinthe. While I normally prefer brut or other dry champagnes, for this drink a little sweetness isn't a bad thing. If you only have dry champagnes, you can also shake a little sugar into the absinthe before adding it to the champagne flute. Following that frame of thought I have also on occasion added a bit of lemon zest for a slight citrusy flavor. Floral accents also do this drink justice, so a touch of lavender mixed in or a rose petal as a garnish really add to the cocktail in my opinion.
Below is the recipe I had used in a proposal for a club;
Death in the Afternoon
Glass: Champagne Flute
Garnish: Rose Petal
30 ml Mephisto Absinthe
Sparkling Wine (Seco)
1/2 tsp fine Sugar
Place the sugar into a mixing glass and pour the absinthe in with it. Swirl the absinthe until the sugar is absorbed. Pour the sparkling wine into a champagne flute until about three quarters full. Pour the absinthe and sugar mixture into the sparkling wine. Float a single rose petal on the surface for the garnish.
One more drink for the Road
Another take on this is one of my favorite shooters, The Green Pixie. I had this at my restaurant in Kathmandu and it is my shot of choice on a night where you don't care if you get up before noon the next day. It's a smaller version of death in the afternoon done in a shot glass, instead of the sugar being in the drink, I would do it with a sugar rim. This gives it a nice contrast and it's in my opinion a very easy shot to put down. Almost too easy.
Glass: Shot Glass
Garnish: Sugar Rim
22 ml Mephisto
Top off with Sparkling Wine (Seco)
Rim the shot glass with a freshly cut lemon wedge, then rim it with fine sugar. Pour absinthe into shot glass and then top it up with sparkling wine. Wait for the mixture to emulsify before shooting.