I'm inclined to think they were an early crafting system similar to potions that was partially cut, but left in for the detail. That's merely speculative. It could have been intended to be this way all along.
Well, that's pretty much what it is. You can use a Cooking Pot or Roasting Spit to combine raw food (and some alchemy ingredients, like salt piles) into finished dishes that have better properties. It's just like alchemy, only doesn't use a skill. Most food is pretty limited, but http://www.uesp.net/wiki/Skyrim:Cooking make fairly potent potion equivalents:
Elsweyr Stew: in a cooking fire, combine 1 Ale, 1 Eidar Cheese Wheel, and 1 Moon Sugar. Effects are:
- Regenerate Magicka 25 pts for 720 secs
- Fortify Magicka 100 pts for 720 secs
In Morrowind and Oblivion, food items were just another type of alchemy ingredient, and drinks were another type of potion. It would have been better if they'd left it at that in Skyrim.