do you have any cookbooks of recipes from 500-1000 years ago? i mean recipes that are exactly the way the dishes were cooked that long ago. not a contempory version of them.
While there are earlier examples most recipe books were generally started around the late 1700s (it was around that time presses got more efficient and cheaper, such that more than kings could reasonably have such a thing) so 500 to 1000 years is a bit harder.
It would also vary by region within a country -- the modern world where we all have wheat flour as much as we want is a relatively new invention (some regions being more suited to barley, oats, rye or other cereal crops than wheat, to say nothing of differences in wheat and modern varieties of it which in many places makes leaven wheat bread a rare Sunday treat rather than costs barely anything in the supermarket. To that end bread for the peasants is more likely to have been some local cereal crop flat bread or even just a porridge/stew). It would also vary by country -- it is generally held that the reason English food is considered bland is not because it being in the arse end of the north sea and the last place spice traders got to but more because when the fields were fertilised it was human shit that did it (as opposed to animals elsewhere) and that is an easy way of getting all the diseases so you in turn get to boil your food for a long time to make sure you don't and with that goes much of the taste.
You also have a difference in methods -- nice temperature controlled ovens are still pretty new so that long ago it would have been open fire and pots/steels on the fire or in the coals, or maybe you go to the local baker and borrow their bread oven (today you would probably know it as a pizza oven). Things were used differently as well -- pastry that might be around a pork pie was less something you might have that makes it nicer still but more a cooking utensil that you would give back to be used for tomorrow, and probably would not taste that good anyway.
Fruits and vegetables also changed somewhat during that time -- modern apples being enormous sickly sweet in comparison mutants of older stuff (though wild apples/crab apples and some heritage varieties represent something more here and are still available) and do you want some watermelon -
https://www.thisiscolossal.com/2015/07/watermelon-painting-stanchi/ ?
That said I do have lists of wild plants and their uses, during world war 2 a lot of the old stuff came back in (see rosehips
http://www.theoldfoodie.com/2014/05/the-rose-hip-collection-campaign-ww-ii.html ), many staple dishes of a given area are now regional dishes or specialities and people still cook with Dutch ovens and the like when out and about. If you want a good one there see some of the spit roasted sweets -- you basically thread various fruits and nuts onto a line, wrap the line around a rod, coat/baste them in honey or similar and roast them on a spitroast, remove the line and have it in a bowl.
You might also have to work harder to get some of the fats used in cooking. You can still get lard, beef dripping (though jelly on it is apparently harder) and the like but you will have to go looking. Not much olive oil (saving that you were in Italy), coconut oil or the like being used. Flax seed, rape seed and the like being more common.
It is also still less than 500 years since potatoes, corn, bell peppers, peanuts and tomatoes appeared in Europe, never mind got widespread. Between 500 and 1000 not that much changed other than words and maybe some preferred dishes (French takeover in the UK and all that) but going further back than that you did have the Romans that did various things (walnuts to much of the place where before they were much more regional), and you might still find some domesticated animals being relatively new.
If you want to go further then the idea that chickens lay eggs all year round is relatively new too (not to mention modern chickens are giant mutants of their original form). Though there were storage methods that meant for the vast majority of the year there was the option to have them. At this point we are also getting into proportions of diets (lot more fish, meat might well have been both less common and different if it was a tradeoff -- the best chickens for most are young chickens but boiler chickens (older chickens) might have been more common if you want eggs and boiler chickens are actually quite tasty if done right, same for various things if you are getting milk from your cow and goat and wool from your sheep, plus again modern breeds* are often quite mutated and probably taste rather different even if you account for the non corn fed stuff. I eat rabbit and would eat hare as well (see jugged hare) but both are uncommon today, not to mention they were farmed after a fashion where today they are wild. Goose, phesant and duck probably also featured differently). Also are you rich in this as that does change things too (probably a lot more venison for one)?
Storage was mentioned above and is a thing as well -- salt cured, smoked and similarly preserved stuff would be in the mix not because it is tasty (and believe me I like a good biltong) but because it was necessary if you are going to have a winter you survive or don't starve through.
*there were also a lot of local breeds that today are rare breeds.
https://poultrykeeper.com/chicken-breeds/ https://www.rbst.org.uk/ . Going onto the mutant thing see the differences between modern dairy and modern beef cows (don't know if we have leather cows bred quite as selectively per se but that too, not to mention the best leather comes from younger animals, or actually probably kangaroos, ask any motorbike type what leathers they would go in for money no object, but that is a different discussion)
Some videos that make a nice start here
the whole playlist is good stuff too