Oysters Bienville

  Oysters Bienville 1 bunch of green onions (green and white parts sliced)2 tablespoons butter2 tablespoons flour2/3 cup chicken stock1 egg yolk1/3 cup sliced mushrooms1/3 cup white wine1 teaspoon salt (or to taste)Cayenne pepper2 dozen oysters1/2 cup fresh bread...