King Richard I was once captured for ransom while traveling undercover trough Austria.

His cover was blown specifically because he tried ordering a roast chicken.

There are a few variations of the details in this story though, a peasant could definitely have owned a chicken and eaten it when it died but it was probably way more valuable to sell it.

Doubtful, most common meal for peasants would have been a sort of stew of vegetables and oats called pottage.

A whole chicken would have been prohibitively expensive either to purchase or in lost money from sale at market, same for pork or beef.

Fish though would be plentiful and cheap and a valuable source of protein. Oysters were considered peasant food until pretty much the 20th century.

Wheat bread similarly would have been a rare luxury, especially made from refined white flour, rye and buckwheat, roughly ground would be far more common.

They'd have access, but you're not wrong, a peasant probably isn't going to waste that much on a single meal.

Yes, they had chickens back then.

A roasted bird? Why not? Y’all are making assumptions that this is a chicken and the peasant a small farmer but why not a traveling mime trapping pigeons from the square?