Hajjlaran

From Memory Alpha, the free Star Trek reference.

Hajjlaran is a hot exotic spice native to the planet Preenos, that is used by the planet's warlords as a test of courage.

The alien trader D'Marr introduced the spice to the crew of Enterprise in 2151, in exchange for, among other things, a protein resequencer.

Chef later prepared several dishes tasted by Jonathan Archer and Trip Tucker using this spice. They both found it extremely hot, so much, in fact, that Tucker noted that Cajun food was tame in comparison. (ENT: "Oasis")

The actual pronunciation of this spice, as well as its spelling in the closed captioning for "Oasis" on the ENT Season 1 DVD, was "Haljaran." However, the closed captioning during the original broadcast, as well as the entry at startrek.com, spell it as "Hajjlaran."