The poor man spinach pie

This recipe reminds one of the recipes for spanakopita. However, the ingredients for this pie are cheaper and therefore, I named it "the poor man spinach pie".

Spinach pie
 
Ingredients
2 cups of plain yogurt (low fat)
2 packages frozen chopped spinach
4 eggs
¾ tsp baking soda
2 tsp salt
1 tsp ground black pepper
3-4 cups of whole wheat flour
1 cup olive oil  

Directions
Prepare the filling by thawing the spinach and squeezing out as much liquid as possible. Add the eggs, 1 cup of yogurt, 1 tsp salt and 1 tsp black pepper. For the dough, mix 1 tsp salt, baking soda and 1 cup of yogurt. Add the oil and incorporate the flour cup by cup. The dough should be soft. Divide it into two balls and roll each batch into a flat layer to cover the surface of a pan (I used a 9x12 inch pan). Spray the pan with oil and put the lower layer of dough. Press with palms if the layer breaks in places. Raise the dough on the side of the pan. Spread the spinach filling and cover with the upper layer of dough. This type of dough tends to break easily; however, this is not a problem. Just arrange the pieces of the dough to cover the filling completely. Bake at 395°F for 40-45 minutes. Cut into small squares and enjoy cold or warm. If dill is in season, adding some to the filling would add additional taste.