• Add all the wet ingredients to a bowl and mix well.
• In a separate bowl, mix all the dry ingredients together. Gradually add the wet ingredients to the dry ingredients until well combined and a dough forms.  
• Knead dough well for 5-10 minutes. Put the dough in an oiled bowl and cover. Fridge the dough for one hour.

Kasha Filling

• In a pan, add 1 tablespoon Olive Oil and the diced onion. Fry on med-low heat for 45 minutes, stirring every 5 minutes.
• Remove the onion and add 1 tablespoon Olive Oil. Add the Kasha (Buckwheat), salt and pepper. Stir well. 
• Add 1 cup of water, bring to a boil and cover. Simmer for 10-15 minutes. 
• In a bowl combine the kasha, onions and mashed potatoes. Stir well.
• Roll out the dough into a large rectangle. Put the filling across the dough longways 2 inches from the bottom.
  
• Egg-wash the bottom and top of the dough and roll longways. Roll the log so that it is closed tightly.
• Use the palm of your hand to create dents in the log every 2 inches. Use a knife to cut where you dented.
  
• Face the dough upwards so the open part is facing up. Use your thumbs to push the dough into the center.
  
• Put on a baking sheet and egg-wash generously. Preheat oven to 375F. 
• Bake for 30-40 minutes until the top appears golden brown.