Heat oven to 350°F Lightly grease large cookie sheet with shortening or spray with cooking spray. In medium bowl, mix both cheeses, onions and olives. Mash with fork to break up any large chunks of cheese. Stir in 1 egg and 1 egg white with fork until well combined.
Separate dough into 8 biscuits; separate each evenly into 2 layers, making 16 biscuit rounds. Press each into 3 1/2-inch dough round. Spoon about 1 rounded tablespoon cheese mixture onto center of each dough round. Fold dough in half over filling; press edges to seal. Place on greased cookie sheet.
In small bowl, beat egg yolk and water with fork until well blended; brush over dough foldovers. Sprinkle sesame seed over each.
Bake at 350°F for 16 to 20 minutes or until golden brown. Cool 5 minutes. Remove from cookie sheet; place on serving platter. Garnish platter with parsley and several olives. Serve warm.