To make ahead: Chicken filling can be made a day ahead. Cover and refrigerate. Assemble and bake pot pies as directed.
To make ahead and freeze: Do not thaw puff pastry until ready to bake pot pies. Prepare chicken filling as directed. Cool slightly. Transfer to freezable storage container. Freeze up to 3 months. When ready to bake pot pies, thaw chicken filling. Thaw and cut out puff pastry. Assemble and bake pot pies as directed.