This was my creation back in 2010 except that it was a whole egg and the rum was Old Monk (it was created for Mixoloseum's Thursday Drink Night with a theme of "dark rum"). My inspiration was the Diablo as well as an egg drink that I had earlier in the week.; to this day, I'm still not sure if citrus invalidates a drink from being a Flip (it certainly isn't a classical ingredient).

https://cocktailvirgin.blogspot.com/2010/04/kroni-berry-flip.html

Curated this to correct ingredients and add attribution, per @yarm's comment above. (For posterity the previous posting had Smith & Cross as the rum and an egg white without yolk.) Thanks!

A reasonable balance, but a little too many different herbal flavors going on in this cocktail.

Curated only to add attribution and garnish. Thanks, Neel M, for the tip.

Updated this as per the recipe in the Death and Co. book, which specifies no garnish.

Thanks,

Zachary

Diego Valencia's Naked in the Desert subs sotol for the mezcal, serves on the rocks, and garnishes with a grapefruit twist and 6 drops Angostura bitters.

A variation I like: Anejo Mezcal, Lemon instead of Lime, and Green Chartreuse instead of the Yellow.  Add a handful of drops (maybe a dash) of Scrappy's Firewater bitters, to taste.

Made this tonight subbing Campari for the Cynar (I'm out) and adding a dash of Bittermens Mole bitters. Really good for those who like Boulevardiers/1794s/Old Pals.

Boozy, and enjoyable.

Very tasty and unique!  Would make again. 

Tried it with a couple different gins. The bitterness of vermouth comes through with Plymouth. Used the Bombay London Dry (not sapphire) and it was well balanced, not too sweet, not too Dry, not too acidic.