Stir yeast and sugar into warm water, allow to stand for 10 minutes – it should get very bubbly.
Meanwhile, in a large mixing bowl: combine flour and salt. Pour in yeast mixture, stir well to combine. Add sour cream, olive oil, and eggs; mix well to combine.
Dump dough out onto a floured surface, knead until soft and elastic, 5-10 minutes. Place dough in a greased bowl, cover with plastic wrap, and allow to rise for one hour, or until doubled in size.
While dough is rising, make your filling:
Squeeze all of the water out of the spinach, set aside.
In a large pan, saute onion in olive oil until soft and translucent. Add spinach and garlic, stir well to combine, cook over medium heat until liquid is completely gone. Remove from heat.
Stir in feta, olives, dill, pine nuts, lemon zest, and nutmeg, stirring until well combined. Add yogurt, stir until completely incorporated. Season with salt and pepper, to taste. Cover and chill until ready to use.
Once dough has doubled, punch it down, and divide it out. We divided the mixture into 6 equally sized balls, – but you can make them smaller by dividing into 8 sized pieces.
Preheat oven to 350 , line baking sheets with parchment paper.
Stretch each dough ball into a round, approximately 8″ diameter. Scoop about ¾ cup of filling into the center (½ cup, if making smaller ones), and fold the edges in to make a triangle, as shown below:
Gently flatten each pie out to about 1″ thick.
Once you have all of your pies formed, set them on lined baking sheets to rise for another 10 minutes.
Whisk egg together with 1 Tbsp of water, brush over the tops and sides of each hand pie. Bake for 30 minutes, or until golden brown.
Serve warm or room temperature, with tzatziki dip, if desired. (I have a great recipe for it in More Than Poutine!). Wrap any unused pies in plastic and chill until use.