Here's our recipe for an open crumb sourdough bun.
Please be careful with adding too much water if you are new to sourdough baking. You can use the same recipe, but with lower water content if you like.

Recipe:
400g strong white flour
100g stonegrounded spelt
400g water
100g sourdough starter
12g salt

Find us at
http://www.simpelsurdej.dk/
or
  / simpelsurdej