1Bake the puff pastry shells as directed on package.
Place oil in large saucepan. Slice chicken into small pieces season with salt and pepper and cook chicken in oil until almost done. remove with slotted spoon and set aside.
2Add butter to saucepan and let melt. Saute the mushrooms, onions, and garlic until softened. Add the wine and let most evaporate. Stir in the flour.
3Slowly add the veal stock whisking constantly. Add the heavy cream and continue to whisk. Once well incorporated add the creme fraiche and vinegar. Stir in the peas. Add the chicken back to pan. Heat through.
4Taste and adjust seasoning. Remove the top from baked puff pastry and spoon the chicken mixture inside the pastry letting it run out onto the plate.