So... a TON of food we associate with "Medieval Europe" was not available in Europe in the Middle Ages.
Taters, for example, PO-TAY-TOES, were an American staple cultivated in Bolivia in 8,000BCE or thereabouts. Europe wouldn't get their greedy hands on them until the early 1500s and it wouldn't become something accessible to farmers until around the 1600s.
Frederick the Great got a hold of potatoes in Prussia, found out how EXCEPTIONAL they were at being great starchy delicious and filling foods with tons of nutrients, and tried to get the Prussians to eat potatoes. They -refused- to touch the things. So he instead hired guards to protect the potato fields but BADLY. Like so badly. People saw the potatoes being guarded and went "Oh. Those -MUST- be good! The King wants to keep them for himself! Let';s steal them!" and that's when the Prussians started eating potatoes... Shortly before the AMERICAN REVOLUTION.
Tomatoes? Same thing. Peru and Bolivia. They spread north to the Aztecs, Mayans, and Mexicans before they spread to the nations of what is now the US. Again, Europe didn't have access to them 'til the 1500s and 1600s. We associate tomatoes with Italian food, but for the majority of time the boot shaped peninsula existed there were no tomatoes there. You could get a BL but no T!
Man, that old Todd Lockwood 3e art piece with the Barfight... what a seminal piece of D&D material! Mindflayer, Beholder, Githyanki, Bugbear, Hobgoblin. Elves and Halflings and Dwarves and Gnomes. Even a Tiefling.
There are two pieces of food in this image. And they're actually the same piece of food. Turkey Legs. COME ON! How many Medieval characters have you seen in TV, movies, ren faires, chawing on a turkey leg? It's CLASSIC. It's QUINTESSENTIAL. It's the most clearly medieval thing you can do. Just hold it by the bone and tear chunks off with your teeth between swigs of ale or wine or sparkling cider at Thanksgiving while your mother looks exasperated at your terrible table manners...
And it's American. Not available in Europe until the 1500s at the earliest, Well into the Renaissance. So at least the Ren Faire got it right, more or less. Because, again, just because it -reached- Europe in the 1500s doesn't mean it was -accessible- in Europe for the vast majority of folks. It was something wealthy people might be able to get their hands on, but nobles and kings could eat a few times a year until much later when people were able to keep them alive long enough to raise them as a food animal and in large enough numbers that more people than the King could enjoy them.
TONS of what we think of as "Traditionally European" foods are actually from the Americas. And mostly from South America, if we're honest with ourselves. Remember Yondolla's Cornucopia?
Corn is from the New World. Maize, specifically, A grass seed not terribly unlike Wheat that they cultivated into many varieties of what we now call Corn. Do you have Whiskey in your setting? It's often made of Corn. Bourbon is 100% corn booze. Rum? Okay that one's Sugar Cane which originated in the South Pacific and actually reached Europe when the Muslims conquered chunks of it in the 600-1400CE range. So I -guess- we can allow Sugar Cane to be in Medieval European Fantasy without it being an anachronism...
But Rum developed in the Caribbean during the 1600s so no rum for your pirates of medieval Europe!!!
Sincerely... All of this stuff has been a part of our perception of "The Past" for so long that our fantasy games that are 'Generally Europe' include them all. Sandwiches aren't going to get you yelled at.
Tacos might. Chinese food might. But that's just because there are racist jerks who have no clue of the history of the foods they associate with Europe getting pissy about "Anachronisms" in a fantasy game where nothing makes any kind of historical sense. It's just an excuse for them to get mad about the existence of people who aren't white, cis, and straight.
And for the record: Sushi and Tacos, at least, are -actually- medieval foods of their respective cultures. Sushi was invented in the 700s as a way to preserve fish by wrapping it in cold rice, and Tacos were created at some point before 1000CE and largely served as street food or "Fast" meals since you could just HAVE tortilla sitting around ready for some vegetables and meat to get slapped into it the instant it was done cooking.
Beef Stew as we know it, today, didn't exist until the 1700s. What they had at the time was Bukkenade. A sad bowl of beef chunks floating in murky looking water thickened with egg yolks and seasoned with parsley, cloves, mace, ginger, saffron, sage, and hyssops (a type of mint). That's right. Minty Ginger Beef.
Anyone gives you guff about the foods that you have in your games, point them to this post.