Mystery Meal for the Merchant
The quest is unlocked after completing The Future of Hyrule scenario.
"You see the Skull Lake merchant in the middle of battle. But he's too hungry to sell anything—and has only spices and can't eat those! Bring him some main ingredients to cook with."
"With your help, the Skull Lake merchant made monster stew. Thought it's got a bizarre color, he thinks it's seriously good creature cuisine. Give the stew a try sometime. He gave you the recipe!"