What are some recipes that peasants/serfs in the medieval period used?

Answer 1

Go here for sites that feature medieval recipes.
http://www.google.com/search?num=30&hl=en&newwindow=1&safe=off&sa=X&oi=spell&resnum=0&ct=result&cd=1&q=medieval+recipes&spell=1

Answer 2

Middle Ages Recipe - Mary Caboges

Boil 8 marrow bones (split lengthwise) in 5 cups beef broth until marrow is soft (about half an hour). Skim off the grease from the surface, and remove the bones from the broth. Knock out the marrow from the bones, and chop it up. Save the pieces. Wash 1 cabbage and chop coarsely. Add the cabbae to the broth, bring to a boil, and simmer for five minutes. Combine in a separate container 1 cup grated toasted bread crumbs, 1/4 teaspoon saffron, a pinch of salt, and 1/8 teaspoon thyme with the reserved marrow. Add this to the cabbage, and simmer for five more minutes. Serve in bowls, placing several small pieces of marrow (called gobbettys) on top of each portion.

Cosman, Madeline Pelner. Fabulous Feasts: Medieval Cookery and Ceremony. George Braziller: New York, 1976.