Heat a heavy skillet over medium heat.
Add a tablespoon of olive oil and the while onions and cook until lightly caramelized.
Dice the sausage and add to the onions. Cook another 5 minutes or until lightly browned. Place the cooked Rose Polish Sausage, caramelized onions, potato, Boursin cheese, dried parsley and Kosher salt into a bowl and mix together well. Place 1 heaping tbls. of sausage potato mixture in the center of the pierogi dumpling wrapper. Brush the edges with egg mixture, fold over and then crimp with fingers or a lightly floured fork. Bring 2 quarts of water to a boil with 1 tsp of Kosher salt. Place Pierogi into boiling water. Once Pierogi begin to float cook for 1-2 minutes. Remove and drain. Heat a skillet over medium high heat then add butter and olive oil. Add shallots, reduce heat to mediumand cook for a few minutes till they begin to caramelize and brown nicely. Add Pierogi and saute till they begin to brown. Add Raisins and Chicken stock. Cook until the chicken stock is reduce in half.