In a food processor place the chicken breasts, salt, and pepper. Pur�e them until a smooth consistency is achieved. Add the eggs one at a time and blend them in well. Add the butter and blend it in. With the food processor still running, slowly add the heavy cream so that it is mixed in well. In a medium bowl place the pur�ed chicken mixture. Add the hazelnuts and mix them in. Place the mousse in the refrigerator so that it chills. Remove the chilled mousse and, using 2 spoons, form it into dozen egg-shaped quenelles. Place the chicken stock in a medium saucepan and heat it on medium high until it almost reaches a boil. Place the quenelles in the stock and cook them for 3 minutes. Turn them once during the cooking process.