Preheat oven to 400°F. Line baking sheet with parchment paper; set aside. Stir together chicken, broccoli, cheese, soup, green onions, Dijon mustard, thyme, salt and pepper; spoon into tart shells. Place on prepared pan. Bake for 20 to 25 minutes until filling is heated through and pastry is golden brown.
Tip: Freeze half of the mini pies for later enjoyment if desired. Reheat pies from frozen in 350°F oven for 20 to 25 minutes or until filling is heated through.