The Society for Creative Anachronism (SCA) has a bunch of people who do medieval food preparation and redact period recipes. If you google "SCA medieval recipes", you will find dozens, if not hundreds, of web pages that not only recreate medieval recipes, but also have figured out what to substitute for stuff that's not available in your neck of the woods and still taste relatively authentic, and with substitutions for those with dietary restrictions (such as diabetic or with food allergies or what have you.)
He's been feeding his Ars group on the occasional medieval meal every few weeks. Chiches, Buttered Worts, Ymbre Tart. And that's just the stuff I remember.
food.com is a recipe website(membership is free)that allows you to put your own recipes on it, the nutritional information is put on there for you & yes I tried it(I'm a member, I have 129 recipes so far).