8 ounces good quality bleu cheese such
    as Roquefort, Gorgonzola or Stilton
12 tablespoons butter, softened
1 teaspoon Dijon-style mustard
1/2 teaspoon Worcestershire sauce
18 to 24 mushrooms, stems removed
Chopped parsley

Combine the cheese, butter, mustard, and the Worcestershire sauce in a small bowl, stirring with a wooden spoon until thoroughly combined. Spoon the cheese mixture into the mushroom caps and sprinkle with chopped parsley.

Serves 6 to 8 as an hors d'oeuvre.