Red leaf tea

From Memory Alpha, the free Star Trek reference.

Red leaf tea is a Cardassian hot beverage, a tea with a garnet-red color and a rather sweet and spicy taste. It was Elim Garak's favorite breakfast beverage, (DS9: "The Wire") and Julian Bashir enjoyed it with his scones and jam. (DS9: "Inquisition")

After dismissing Chief O'Brien's assistance, Gilora Rejal asked that he retrieve some red leaf tea for her. Acknowledging the not-so-subtle dismissal, the Chief complied. (DS9: "Destiny")

In the middle of a crisis on Deep Space 9, Dukat ordered red leaf tea as he was mocking the crew stationed in Ops. (DS9: "Civil Defense")

Red leaf tea might be a variety of Red Bush tea, an African beverage with similar color and flavor.