Step 1: Preheat your oven to 400°F (200°C). Roll out the defrosted puff pastry on a lightly floured surface and cut into 3x3 inch squares.
Step 2: In a mixing bowl, combine the cooked chicken, chopped celery, buffalo wing sauce, ranch dressing, mayonnaise, and cheddar cheese. Mix until well combined.
Step 3: Place a tablespoon of filling in the center of each pastry square. Fold and seal the edges with a fork.
Step 4: Place the puffs on a parchment-lined baking sheet. Brush with melted butter or egg wash. Bake for 15-20 minutes until golden brown.
Step 5: Let the puffs cool slightly before serving. Enjoy warm or at room temperature!