1) In a large saucepan over medium heat, melt 55g of the butter, and saute the shallots until softened, about 4 to 5 minutes. Sprinkle in the flour, and cook, stirring with a wooden spoon for 2 minutes. Whisk in the sherry and broth and bring to a boil while stirring. Add the parsley and thyme sprigs, lower the heat to maintain a gentle simmer. Cook the sauce for 30 minutes, stirring frequently.
2) Meanwhile, heat the remaining butter in a large skillet over medium-high heat, saute the mushrooms until golden brown, about 5 minutes. Season with salt and pepper. Strain the sauce into mushrooms and season with the salt, pepper, cayenne, and nutmeg. Whisk in the creme fraiche.
3) Add the minced parsley, chicken, and chives to the sauce, and bring to a simmer. Adjust seasoning with salt and pepper. Serve immediately over noodles, toast points, split baking powder biscuits or wrapped in crepes.
4) For the poached chicken: Put the parsley, thyme, onion, carrot, celery, and chicken breasts in a medium saucepan. Cover with the broth, and bring just to a boil. Lower the heat to very low and cover. Poach the chicken for 20 minutes or until firm to the touch. Remove the pan from the heat, uncover, and cool the chicken in the liquid for 30 minutes.
5) Transfer the chicken to a cutting board and reserve the liquid. Bone and skin the chicken and cut the meat into cubes. Discard the bones and skin.
6) Strain the broth and store, covered, in the refrigerator for 3 days or freeze for later use. Remove any fat from the surface of the broth before using.