In the 13th century, breakfast when eaten sometimes consisted of a piece of rye bread and a bit of cheese. Morning meals would not include any meat, and would likely include 0.4 imperial gallons (1.8 L) of low alcohol-content beers. Uncertain quantities of bread and ale could have been consumed in between meals.
Reject modernity, return to tradition
Small beer, local cheese, and fresh bread. Throw some beans in there and I'm on board
Sounds like the breakfast of champions to me.