Breen is an animal native to Narn and is the main ingredient in a ground meat delicacy of the same name.
Breen is identical in smell, taste and appearance to Earth Swedish meatballs and Centauri Prime's Roopo balls. Ko'Dan considered the "perfect" breen to be "soggy but meaty" and never crunchy. 
In December 2258, two Techno-mages named Galen and Isabelle were in desperate need to make authentic breen to bribe another Narn captain by the name of Ko'Vin. They impersonated chefs and claimed to be from the Chemical Culinary Institute and claimed to be visiting Ko'Dan because he had won a cooking contest. Their first attempts at making fresh breen were failures, and they worked with Ko'Dan through the night well into the morning on creating the "perfect" breen.
Officially the provided image is actually Swedish meatballs, but since Na'Kal confused it for the real thing it must look close enough alike to be a fair representation.