Beat the cream with the feta cheese feta cheese blue cream until smooth. Sprinkle with pepper and confused. Take a spoonful of the mixture, put the hand, fingers spread, put in the middle of grape and grain shape ball, as nipple cover well with the mixture of cheeses. Shaped ball roll in chopped walnuts. Same Repeat with remaining mixture and grapes. Arrange the balls on a plate and refrigerate for at least one hour before serving.