Snail juice
From Memory Alpha, the free Star Trek reference.
Rom was especially fond of snail juice with extra shells (DS9: "The Ascent", "Doctor Bashir, I Presume"), whereas Quark liked his snail juice extra smooth. (DS9: "Business as Usual")
The first thing that Rom ordered at his brother's bar in 2372, when he was no longer working there, was a large snail juice. (DS9: "Bar Association")
At the end of the year 2372 Quark offered Rom a snail juice on the house. He behaved in that uncharacteristic way, because he thought he was dying. (DS9: "Body Parts")
While journeying to Risa aboard a runabout in 2373, Quark ordered a hand-pressed snail juice from Leeta. She told him to get it himself, as she was on vacation. (DS9: "Let He Who Is Without Sin...")
