Saffron

Saffron is made from the stigmas of crocus flowers, which grow exclusively in the Troll Homelands. 1 pound of saffron requires around 200,000 stigmas, or around 70,000 flowers worth, which explains why the plants are so hard to cultivate outside of their native climate in any worthwhile amount, and also, along with transport costs, why it is more expensive than its weight in gold.