I found this recipe on liquor.com.

gin, green Chartreuse, maraschino liqueur, lime juice⁣
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A Prohibition-era gin cocktail that uses a liqueur made by monks in France using a 400 year old secret herbal recipe. Really.⁣
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Carthusian monks at Vauvert, near Paris, were given a recipe for an “elixir of long life” in 1605. It has since then been used to produce the “Elixir Végétal de la Grande Chartreuse”. The formula is said to include 130 herbs, plants and flowers and secret ingredients combined in a wine alcohol base.⁣
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The Last Word has been suggested to me as a “must try” based on other drinks I like, but I was hesitant to buy the Chartreuse. Some people say it has a strong black licorice flavor, or that it’s overwhelmingly medicinal. Neither of those flavors are appealing to me. Plus, it’s expensive! In the end I decided that I’m saving so much money not eating out during quarantine (not even takeout), I might as well allow myself all of the weird liqueurs I want to try. ⁣
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And Chartreuse isn’t medicinal tasting, and doesn’t taste like black licorice. It is WOW amazing. This cocktail is delicious! It is gin-ny, and herb-y, and a little bit sweet. I am really looking forward to trying other drinks that use Chartreuse. ⁣