Roasted Moongraze Tenderloin is a low level cooked food item which can usually only be obtained by cooking a [Moongraze Stag Tenderloin], a meat that can be obtained from Moongraze Stags and Moongraze Bucks in the draenei starting zone Azuremyst Isle.
This item can be created by cooking, and is also a quest reward. The recipe for cooking this item is obtained in the same quest in which the item is a reward:  The Great Moongraze Hunt.
Cooking Roasted Moongraze Tenderloin
This item is crafted by Cooks. There is no minimum skill level for this recipe - you just have to have the Cooking skill.
The components are:
Roasted Moongraze Tenderloin as a Quest Reward
Roasted Moongraze Tenderloin is quest reward for  The Great Moongraze Hunt in the draenei starting zone Azuremyst Isle. The quest starts with a draenei named Acteon at Azure Watch.