Preheat oven to 350°F.
Combine mustard and breadcrumbs in bowl and blend thoroughly.
Spread some of mixture over entire surface of hens, patting firmly with hands.
Spoon remainder into cavity.
Sprinkle with parsley and dot lightly with butter
Place on rack and roast until tender about 1 1/4 hours.
If coating starts to overbrown, tent with foil.