Pre-expansion, I compiled a guide to the Cooking Achievements that lead to the "Chef" in-game title. After skilling up my cooking on multiple characters, I've discovered that at least three of the required recipes for the Northrend Gourmet achievement do not appear to be currently attainable -- Kungaloosh, Fish Feast, and Orca Stew.
There are quest chains that reward you with a stack of Kungaloosh and Orca Stew, but neither quest provides you with the recipe to make those items. The Fish Feast looks like it should be a Dalaran Cooking Awards purchase, but it's not on the vendor. Since the achievement requires you to make 45 of 46 possible recipes, these omissions would make this achievement not possible. I have a GM ticket turned in on this topic and will report back if they let me know how this issue is going to be addressed.