Venison Pierogies

A couple weeks ago, my mom and I went on a pierogi making spree.  We made 4 different kinds and more than 150: dill havarti, pork and sauerkraut, bacon and cheddar, and venison.  They were all definite winners.  It's hard to pick a favorite because they are all unique.  If I had a food truck, it might be a pierogi truck.  Nashville would benefit from it.

Dough
5 C flour
16 oz sour cream*
2 whole eggs
1 egg yolk
3 Tbsp butter, melted 
1 tsp salt

   Combine everything except flour.  Add 4 1/2 C flour.  Incorporate.  (The dough probably will not form a ball on its own.)  Sprinkle 1/4 C flour on surface.  Turn out dough.  Sprinkle the last 1/4 C over the dough.  Knead dough until it comes together and is smooth (~3 minutes).  Add more flour if needed.  Divide dough into easily managed pieces (2-4).  Let rest at least 10 min. in refrigerator.
   On floured surface.  Carefully roll out dough to 1/4 inch thick.  Cut into 3 inch circles.  
   *Reduced fat sour cream works, but do not use fat free.

Venison Filling
~3/4 lb ground venison, cooked and seasoned with salt and pepper
8 oz porcini or button mushrooms, chopped
1/2 C diced onion
2 tsp minced garlic
~1 1/4 C stiff mashed potatoes
6 oz crumbled blue cheese

   Saute onion and mushrooms until onions are translucent, 5-7 minutes.  Combine all the filling ingredients.  Season with salt and pepper to taste.
   Fill pierogies with about 2 Tbsp of mixture.  Seal into half moons.
   Boil until they float.  (At this point, you can freeze them.)
   Makes about 4 dozen.  (Serving size=4)
Finishing (for every 2 servings):
   1 medium onion, sliced.  Saute in butter or oil until soft and sweet, about 10-12 minutes.  Add pierogies, lightly brown on both sides and heat through.  Add about 1/4 C water and 2 Tbsp sour cream to make a sauce.  Sprinkle with parsley.   

Use this post as a more detailed reference.