Pimm's Cup at The Boathouse

anyone know how the Boathouse makes their Pimm's Cup? Ms. Coasts has taken a liking to it, but can't replicate it at home. We plan to ask next time we're there, but curious if anyone here knows.

as it were, i ran into a chowhound while there. hello Mike! I owe you an email about duck!

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Central Park Boathouse
Central Park East Drive E 72nd St, New York, NY 10021