First, make your hibiscus syrup (see recipe below).
Add ingredients to a small/medium size saucepan over medium heat, stirring until sugar has dissolved and it comes to a boil. Remove from heat and let steep for 1 hour. Strain mixture. Syrup should keep for 1-2 weeks in a refrigerator.
Crack your egg and separate, adding the white to the larger side of your cocktail shaker. In the smaller side, add the lemon juice, hibiscus syrup, and gin. Combine the two shakers together and dry shake for 30 seconds. Dry shaking is important with egg white cocktails because you want to fully integrate the egg whites into the rest of your ingredients properly. Open your shaker, add ice, and shake again. Shake hard and long so you get a very nice stiff foam on top of your drink. Strain into a coupe glass.
To garnish it with a bitters heart you will need to make a stencil. It is quick, easy, and inexpensive. I first did it for my Halloween post and I’ve been wanting to make another one ever since. You will need a plastic lid, X-Acto knife, marker, and an atomizer to put the bitters in. I printed out a heart shape that I liked and traced it onto my plastic lid. If you are confident in your heart drawing abilities, by all means, you can freehand the heart. Cut out the heart by using an X-Acto knife.
Fill an atomizer with angostura bitters. Place the stencil right on top of your cocktail and spray your bitters directly on top. Now you have the cutest heart garnish!