There is one worthwhile cooking/food item:
Elsweyr Fondue provides a massive Magicka boost with an absurdly long duration.
Other cooking items are primarily just low level health and stamina consumables and can easily be ignored unless you're serious about role playing.
Other than that, it's just another crafting mechanic that DLC and modders can easily hook into, so we might see more useful stuff in the future.
gaming.stackexchange.com/users/3129/LessPop_MoreFizz
Quoting Cooking is Overpowered on YouTube: Cooking in Skyrim is not at all the worthless skill it is made out to be.
The benefits of stamina regeneration are huge, while the value of fondue to a caster is more than you might realize.
Summary:
Apparently power attacks only require one point to be activated, which makes the long lasting Stamina Soups more useful than they appear to be.
While under the effect of the soup, you can chain power attacks for twelve minutes.
Eslweyr Fondue increases your Magicka by 100 points, also for a duration of 720 seconds (12 minutes).
This "saves you 10 levels worth of points that you do not have to invest in Magicka".
Well, that is if you can be bothered making the food in the first place.
Personally I couldn't be bothered hunting for Eldar Cheese Wheels when I am already overwhelmed with Smithing, Enchanting and Alchemy.
But when those skills are maxed this could be fun to play with :)
gaming.stackexchange.com/users/1657/Bleep Bloop
There is no cooking skill, however there are a few benefits of cooking over Alchemy: ingredients are more plentiful, and there are less options
the ingredients by themselves will heal you (for a much smaller amount) even without cooking several foods (my favorite being Apple Cabbage Stew)
restores both health and stamina still with the same simple ingredients
the effects of food and ingredients don't have to be discovered, they are always known cooking can't fail and cause you to lose ingredients
gaming.stackexchange.com/users/5994/Pithlit
Food helps restore your stats like life, stamina, or magicka.
Cooked food provides more substantial benefit compared to raw ingredients.
For example vegetable soup helps restore health and stamina 1 point for 720 seconds.
Home cooked meal helps restore all three stats health, stamina and magicka for a certain amount of time.
Earlier in the game I was relying on home cooked meal, but as my character progressed I rely mostly on potions, spells or enchanted gear.
gaming.stackexchange.com/users/15184/Lore Friendly
There is no skill tied into cooking.
It is helpful in the beginning when the player may not have many health potions as it upgrades food quality.
At later levels, though, potions are very affordable and cooking is not required.
It is not possible to add poison to food.
gaming.stackexchange.com/users/14291/Skizzlefrits
Beef stew, venison stew, vegetable soup (which is particularly handy as it requires only cabbage potato leek tomato, no salt or garlic).
The the health benefit doesn't stack, but the stamina does.
That's Huge for stuff you can make by picking up super common items while you're looting, stopping for 2 seconds at a cook pot... AND neither the ingredients or final products have any substantial weight.
All benefits last 12 minutes.
gaming.stackexchange.com/users/87837/Jason Edwards
Cooking is great when you're at low levels!
At the beginning of the game, you won't have many potions available and just going to your local alchemist and buying all their healing potions is too expensive when you start out.
Food items, though, can be picked up for free in every barrel or bag in every house, giving you a much cheaper alternative.
gaming.stackexchange.com/users/142194/Kindra
The amount of health restored is quite low compared to the hassle of getting the ingredients.  Is cooking tied in any way to a skill so the health benefits become better later on?  Finally, is it possible to add poison to cooked food?
What is the point of cooking food?
gaming.stackexchange.com
<the-elder-scrolls-5-skyrim>
gaming.stackexchange.com/questions/36555
gaming.stackexchange.com/users/3917/l I
Cooking is great when you're at low levels. Food helps restore your stats and cooking gives more substantial benefits than raw ingredients. Cooked food cannot be poisonous, affects several attributes and seems to be useful at a lower level.
It is suggested that cooking could be useful at lower levels. Cooked food benefits several attributes more effectively, compared to raw ingredients.  There is no way to add poison to food.