BOIL the water, salt, sugar and butter together. Transfer to a bowl and add the flour while whisking. Mix eggs and crème fraiche and temper into the dough. Rest 30 minutes before use.
SHRED the meat and mix with the potato, shallots, salt and pepper. Taste and season. Set aside.
ZEST the blood orange into the yogurt. Heat a small saucepan and squeeze blood orange juice into it. Reduce the juice to a syrup. Combine syrup, yogurt and crème fraiche to make the sauce.
ROLL the dough out and cut out 5" diameter circles (you can vary the size) with a a cookie cutter. Fill with the duck and potato mixture and seal using a little water.
PAN FRY the pierogies in oil, the will puff and color beautifully. Spoon the yogurt over the top and serve with a side salad.