I've been a bit too preoccupied with my job situation, and with holiday visitors, to dwell on historic cooking projects, but the other day I ran across a blog associated with the Ringkøbing-Skjern Museum, a Danish museum that engages in a lot of Viking lifestyle-re-creation types of projects. The blog published a Viking flatbread recipe they have experimented with. It uses one part wheat flour to two parts rye flour, along with a bit of honey, a small amount of cardamom, and a handful of raisins for flavoring. The flatbread recipe can be found in this entry, and I intend to try it out at my first opportunity, because it sounds tasty (even though I'm not convinced that most Vikings would have had cardamom handy).
In addition, the Museum's Shop features another cookbook with putative Viking recipes. They describe it as "a cookbook for the modern Viking". The cost is about $30 USD (before postage), but since the book is written in Danish, I don't expect to be purchasing it anytime soon. If I change my mind and obtain a copy, I will write about it here.