Cut a pocket in each of the cooked chicken breasts. Prepare a filling with two-thirds of the sautéed mushrooms, the onion, parsley, dried bread crumbs, heavy cream, and salt and pepper to taste. Stuff the breasts with this mixture.

Flour the stuffed breasts, roll in fine cracker crumbs, dip in beaten egg seasoned with salt and pepper, and finally roll in fresh bread crumbs. Quickly brown in clarified butter.

Prepare the sauce: Cook the reserved mushroom stems in water to cover for 10 minutes. Strain and set aside. Melt the butter in a saucepan, and blend in the flour. Cook for a minute or two, then add the scalded milk, heavy cream, and chicken stock. Cook, stirring constantly, till well thickened. Add ½ cup of reserved mushroom liquor, the remaining sautéed mushrooms, and the Madeira. Correct the seasoning. Stir until blended and heated through.