I would imagine much of what ends up in a recipe is because the ingredient is available and someone wonders how it will taste in a recipe. That is kind of how this bread came about. I have lots of pistachios and figured that they would be good to put into a bread. My mind wandered back to when I was a youth and I tasted my first pistachio and how good it tasted. I didn't know until years later when someone told me of a recipe from the middle east of how to roast pistachios. The secret is to soak the pistachios in lemon juice then roast them. This tasted just like the pistachios from my youth. The reason why you don't see pistachios done this way with domestic pistachios is that the lemon juice stains the shell and makes it look ugly. The producers from the middle east dye the pistachios red to cover up the stain.
The pistachio bread that I made has the pistachios soaked in lemon juice. I also made lemon zest from the skin and put it into the dough. Here is a picture of how the loaf looked as it came out of the oven.
You can read more about it here. http://oakflatsourdough.homeunix.com/index.php/2009/Bread/pistachio-brea...