Preheat oven or grill to 375°F.
Allow puff pastry to warm at room temperature until just malleable, but still very cold. Place puff pastry sheet on a dry cutting board.
Cut puff pastry into 24 rectangles about 2" long and 1" wide. Using a ruler and pizza cutter makes the pastry cutting much easier.
Lightly sprinkle celery salt over all pastry rectangles. Cut pickle chips into slivers and put about half a pickle down on each pastry rectangle.
Place mini hot dog down on pastry rectangle and pickle making a lowercase "T" shape and wrap around the middle of the hotdog making a ring, or blanket.
Transfer mini hot dogs wrapped in pastry with pickle to a baking sheet sprayed with non-stick food release.
Paint all exposed pastry with egg and water mixture to coat and then sprinkle with poppy seeds.
Bake for 15 min or until puff pastry becomes golden brown. Serve while hot with mustard for dipping.