HEAT oven to 400°F.
MIX cream cheese, dressing and mustard in small bowl until well blended. Add turkey and mozzarella; mix well.
PRESS or roll out each biscuit to 3-1/2-inch circle; top with cream cheese mixture. Fold each in half; firmly press edges together to seal. Place on baking sheet.
BAKE 10 to 12 min. or until lightly browned. Serve warm.