Also called Osyrat Kornbröd, Viking flatbread made from barley flour is pretty simple to make. It only has two ingredients and, though originally meant to be cooked on a stone over an open fire, can be made on the stovetop with a skillet pan or baked on an oven sheet. All that goes into it is barley flour, which I found at my local bulk food store but can also be found at health food stores and larger grocery stores, and water; in a three parts four to one part water ratio. A manageable amount that makes eight servings is 1.5 cups of flour and .5 cup of water.
Once a stiff dough has been formed divide it into balls around the size of a walnut or a golf ball and roll it out as thin as you can make it. My favourite tip for rolling dough easily (you start googling tricks when you’re in charge of the Christmas sugar cookies every year) is to place the dough between two pieces of parchment paper. Not only is it easier to roll, and doesn’t make as much of a mess, it won’t stick to your rolling pin or your counter. Cook the bread on high heat for about 30 seconds on each side or until golden brown. It’s best eaten right away while it’s still hot but can also be frozen and reheated.
I originally found the recipe, along with a lot of fantastic information on Viking foods, here: http://www.vikinganswerlady.com/food.shtml#BarleyFlatbread