Green Meat

You peer into the bubbling pot, its rank smell almost knocks you off your feet. The nearby ghoul chuckles and slaps the loose skin of his gut, "Good eats, I make the best! You know what really hits the spot in my gut? Brains of them that ain't usin' them! Y'see, use yer brain too much and it gets spoilded and is no gud to eat. Everyone knows the greenies don't use dere brains too much, but there's one lot of greenies that have unspoiled brains!"

Nathore Gristlechewer mentioned something about the best place for 'unspoiled brains' being down in the Dragonbacks. Find some meat that will suit his tastes and return to him in the Wolfshade Swamp of Ostland.