Preheat oven to 425° F.
Dice potatoes, carrots, celery, onion, and zucchini. Set aside separately.
Boil potatoes until nearly soft, and sauté remaining veggies until tender. Mix the two together, then season with pepper.
In a medium bowl, whisk together soup, sour cream, and yogurt.
Drain chicken and add to soup mixture, along with all the cooked veggies and the frozen peas. Mix well, then equally divide among small ramekins, souffle dishes, or oven-safe bowls.
Unfold puff pastry onto work surface and roll out into a 12-inch square. Cut square into 8 equal, smaller squares.
Top each ramekin with pastry, folding the edges down onto the rim of each dish.
Whisk the egg in a small bowl, then brush egg wash over the top of the crusts (but not the edges).
Cut a small X in the center of each crust, and pierce all over with a fork.
Bake 15-20 minutes until tops are golden brown and filling is heated through.
Serve with pears on the side.