I've reached 289 and i still have some green tier recipes but the next thing i can get from the trainer is level 320. So what do i need to do to level cooking?
Edit: Errr sorry i didnt think to check the Ah for recipes, there is some pretty crappy ones but it is possible to level.
In case you or someone else is still looking for a solution and don't want to spend money to buy some recipe at the AH you can always do this quest ( http://www.wowhead.com/quest=8313/sharing-the-knowledge ) in Silithus that provides you with a recipe (285-300) that allows you to level up cooking till the point you can go outlands.