What did monks in the middle ages eat for breakfast?

Answer 1

Most everyone who was not well off ( monks were very poor) ate barley soups, rye or barley bread ( wheat was too expensive) and oatmeal for their meals. Sometimes they were lucky to have a bit of meat, fish and some vegetables.

Answer 2

The vast majority of monks in the Middle Ages were Benedictines. Benedictines were forbidden by the Rule of St. Benedict to eat anything before mid-day.