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Tomatoes are not actually that prevalent in traditional Italian even after Columbus (although they are certainly used to great effect). What you probablu think of as Italian food is actually more of American Italian food.
Italian food varies greatly across the country and is primarily what is available locally.
Seafood and fish is very common. Ancient Romans had a love of a fish sauce called liquamen or garum which they seem to have put on everything. Other meats such as pork and lamb and quail appear more inland.
Olives and olive oils plays a large role and are actually generally the more common pasta sauce.
Grain and eggs used to make pasta.
Cheeses and eggs would've been much more expensive, but they would have been eaten.
Vegetables and herbs like onion and lovage and rosemary were used.
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