The best food is the food you can get the most of! 20 minute crops are great for rapidly increasing your food supply. That's Corn, Pumpkins, Leeks... And you get more per harvest if your crops are watered and composted by harvest time. You can check out the Gardeners Guild if you need help with snacks, so Bigs and Tiny will mind your fields. :)
Fishing is a good place to start, too. Pay Koda and fish by hand, then take your fishy friends to Thumbs in the cooking profession to increase their stamina recovery. Raw meats heal less than cooked!
It is tough to support yourself solely on food you collect from running through Campaign, so you'll want to get your other professions up and running in the meantime. I can also send you some raw meat to get started with cooking. Good luck!
If you're at level 12 farming, I personally believe broccoli is the best crop to grow for energy. It grows fairly quickly, gives a decent yield once fully leveled, and 10 stamina. Cooked fish is the best recipe to cook. Another thing I do is buy all the food in the mole market every time I go, if that's something you can afford right now. Start investing in lots of wolves, level them up through campaign, and equip them with leveled companions. You can play with them periodically and get a good chunk of pebbles! And some companions reward food as well.
If you aren't talking farming-- which trade the inconvenience of mobile game timers waiting for the food to grow for the ability to shove them in your dogs without also cooking them-- the best foods efficiency wise are just plain old "simple reciple" cooked meat and fish. This wouldn't be the case if "higher tier" and complex recipes gave you more items per craft to compensate for how many cooking slots they take up, but they don't, so you can only make a limited amount at a time and it VERY quickly becomes more of a hassle than it's worth. It's a lot of wasted time and effort if what you care about is your time and efficiency of Potential Stamina Per Cooking Slot.
It's impossible to beat, mathematically! The only thing that really gets close are nut feasts, and even then, you're better off just feeding the nuts to your dogs raw and using the time and space to cook more raw meat, lol.
The stamina economy is the game is kinda broken, but the only ways to fix it would also make the game excessively punishing for new players, so until someone clues in that we need extra crafting procs to make the better recipes actually worth anything, it's what we got!