Cut onion and bacon i to very small piecces. In large skillet, saute bacon until crisp. Drain. Remove to holding pan. Cook onion in enough water to cover until translucent. Add to bacon, cover and chill.
Allow ffrozen dough to thaw and rise according to package directions. Punch down dough. Divide in sections for easier rolling.
Flour pastry board. Roll dough with floured rolling pin until 3/8" thick. Cut with round biscuit cutter. Put a tea spoon of cooled mixture in center of each circle of dough and fold over. Crimp with fork. Place on lightly greased baking sheet. Let rise again until doubled.
Bake in 375 degree oven for 15 minutes or until a light tan c olor. Brush with mixture of egg yolks and water. Return to oven and bake until golden brown.
Serve hot. Offer a good ,German mustard if desired.