I recall back in the day the early MREs that did have freeze dried portions, these were mainly the fruit which were freeze fruit mix, peaches and then later strawberries. The main meals that were freeze dried were the pork patty and the beef patty, about a 2 inch square of something that tasted like hamburger or pork sausage. These meals also came with freeze dried ketchup, a buillion package and a pack of beans.
As for cold weather rations, these had, nuts, fruit mix, beef jerky bits, cocoa powder, bullion broth mix and a couple packets of fruit soup mix.
The main meal regular MREs ALL had beverage powder base, fruit, grape, lemon lime and orange along with cocoa and coffee.
A thing about not using the cold weather/arttic rations in the tropics. I would preffer them since most of the food items where small snack type foods, alot lighter, less water needed to process vice regular MRE's, in my view, I could probably live for five days in the field with just three cold weather MREs since you preffered to snack rather than sit down, eat whole MRE ration which is what we would get in the jungle.
As for localy made rations:
Fred beat me to it. I would go with peas, beans and some grains or cereals since they are easily preserved and can be made into soups or breads with grinding or milling into flour. And those two items would be the in my view the two most comon types of food because again as Fred said crop yeild and the ease of which they are preserved. So, alot of bean, pea, barely and corn soup and bread made from the grains would be the most common food stuffs.
Other items like potatoes, fresh corn, turnips, cabbage, other assorted root crops would be decent as they do keep for a bit in root cellars, even apples as well. But these will not keep for longer periods so they will be used within a month, maybe two after harvest.
I can see other prepared foods like cheeses being used, hardbreads like the hardtack mentioned, maybe even dried foods <addressed later> and even some preserves, boiling fruit or some other vegetable and fruit items into preserves that can be canned for long term storage <and providing something come mid winter when no one has had anything fresh in weeks>
Dried foods!
I personaly love the sundried tomatoes they have at the market, but alas, they are quite expensive. Granted, they are not freeze dried. But people have been drying food as a means of preservation for millenia, I have posted on the other sites about one of my early profs in college who went on an archeological dig in S. America and the archeologists made him potatoes for breakfast. Then they asked how they tasted, then how he felt. It turns out the potatoes they fed him were from a find they found in a cave the day before that were in excess of 800 years old.
I can see some communities processing some foods and drying them. They would need sunlight, screens to protect them from birds and insects <although the attracting of birds could be a secondary benefit immeidatly, Sparrow Stew, Fried Swallow etc, catching the birds that were attracted to your drying foods> I read a 1950s era cookbook actualy a series my uncle left me <3 really> and it covers foods from around the world, their history, preparation etc, with PHOTOS! And it shows some of the drying screens used for some items, simple wicker or bamboo screens that the food item is pressed between and they are set where sun and air can do their work drying the items. Others, are set on racks in the sun, and others are placed on the roofs of the houses. A couple just skewer them and hang them, or string them on a line. It all depends on the culture and the item.
However, the time and space to process in this way can be a limiting factor, as well as storage space since the game takes place in N. Europe which is usualy wet, storage space would be another factor. How much can you store successfully where it would not be exposed to moisture and rot?
Another means of preserving foods could be pickling and salting foods. A vinegar brine or a salt brine or combination to make pickled vegetables like carrots, cauliflouer, carrots, olives, mushrooms and of course cabbage and pepers, sauer kraut and kimche would also be good....well not good
but a break from a dull diet, lack of vitimins due to a lack of fresh vegetables and of course improving morale too.
Another method wines and fruit concentrates preserved with alcohol.
As for meat, that would be pretty rare beyond fish, fowl and rabits unless one caught the odd snake or squirrel or such. Or of course you raided an enemys farm, or you had the bad luck of having an animal go lame or be killed for whatever reason.
I can see small stoves much like the Yukon stoves they issue for cold weather training being common. A rectangular box about 2 feet long, cut say 2 or 3 holes in them large enough to place a metal bucket or pot and then start a fire in your box to start the cooking. 1 pot could be for a stew or soup, a second for a hot drink, a 3rd for bumplings, or even making something like dutchover bread, or just add that inside with the coals to cook biscuits, all of which would be doable in a container about that size and enough to feed a squad I think.
On the "Good Luck You're On You're Own" campaign I am playing in I found some Russian rations from their sting in A-Stan and they seem much more T2K'ish than MREs. A package of porridge, a small package of tea, lump sugar, sausage or tinned meat and some crackers. I can see that being something that would be common in T2K.
A standard field ration would be kinda like our K-Rations of old. Used only when needed.
I can see troops being issued metal tins like bread and butter tins like they did in WWI and WWII and even earlier.
A container for porridge, add water and wait
Bread box to hold hardtack or hardbiscuits
Meat container to hold a piece of saltpork, dried fish or sausage
Butter Dish <the cows and goats are saved for cheese and butter>
Oil bottle, cooking oil for frying in your new messkits, oil adds flavor, helps cook and is a source of calories, in a T2K world calories are not to be wasted, so the grease and oil left over from when you cooked that piece of saltpork you found in that marauders pack, well that bacon grease would go nicely with some potatoes.
The trooper may get one mess kit of food for that day that is premade, but the next day its up to their section or squad to make fresh rations daily consisting of say half a dozen potatoes, a couple carrots and an onion with a diced sausage.
I would say that even that porridge ration would be used sparingly because of the time it takes to make.
Then again, someone with the ability, time and materials could make a nice profit from making hardtack, dried sausage and instant soup or porridge.