Vegetable Soup, Venison Stew, Beef Stew give you the ability to use power attacks without worrying about stamina for 12 minutes (real time).
Elsweyr Fondue is comparable to potions with its power (25% regenerate magicka, +100 fortify magicka) and lasts for much longer (12 minutes).
More importantly, they can be stacked with potions
All the time. It's why I hoard salt like I had to pay a Legion's salary.
Role playing demands it, since no one realistically eats raw rabbit haunch, venison, fish, or chicken unless absolutely necessary.
I only play mages, so Elsewyre Fondue is the only buffing consumable I even bother with. Potions don't last long enough for me to justify their use while roleplaying. A half a pound glass vial of expensive liquid to carry around for days/weeks/months through all manner of rugged terrain and situations where it could break, only to last for 30-60 seconds and give me a mild boost? Not worth it.
A half pound piece of food I can eat normally, get nutritional value from, and with an effect better than most potions that lasts twelve whole minutes? A bowl of cheese, magic sugar, and booze? Always worth it. Get a nice bit of crunchy bread to spread that shit over and munch away before I do anything dangerous while swigging even more booze? As good a last meal as any other.
Beef Stew an Vegetable Stew are the same, but less useful to me.
Precisely what I tend to make as well. I usually try not to carry a crazy amount of soup and potions, so I make it in bulk and will swing through and pick it up when I'm running low or after a particularly gnarly dungeon.
I keep potions in a barrel and food in another.
Ingredients are pretty easy to find too. I just get annoyed when I find a SLICED wheel of Eidar cheese instead of a WHOLE wheel. Heavy, only restores 15 points of health... basically useless.
I have experimented with the cooking element for my first two characters (Melindora and Vani), but only my arrowsworn Danvir currently takes it seriously, mainly for RP'ing which I didn't do much of with the first two.
Generally he knocks up a vegetable soup or apple cabbage stew at Dragonsreach when he's in Whiterun, then stores them in earthenware flasks to eat while he is travelling.
I do occasionally, and then immediately forget that I'm lugging around like 10 Beef Stews or whatever.
It's the same problem I have with potions and scrolls - remembering to use them. Except it's worse with food, since I'm really not used to looking in the "Food" section of the UI.
I do wish that the food was somewhat more balanced. What's the justification for one type of food to restore 10 points of Health and a slightly different type of food to restore 1 Health and Stamina per second for 720 seconds? Some recipes seem useless while others seem decent - just doesn't make sense.
I used the Ritual Stone's daily power.
Recently I went through a deep and immersive playthrough the like of which I haven't experienced for a year or more and cooking was a big part of that. I haven't really explored the Hearthfire side of this, but I forgot what an "I win" food some of those stews you can make are. Stun-locking a Frost Troll while on the path to High Hrothgar reminded me just how great the meals are. Especially if you have rp'ed the crap out of it in the run up to preparation. The hunt, the kill, the finding of a camp and place to cook outside... Magic moments on their own but much better when the pay off is so sweet later.