Pre-heat the oven to 400 degrees. Line a baking sheet with parchment paper (or aluminum foil misted with cooking spray) and set aside.

Place the butter in a small saucepan and bring over medium-low heat until the butter is melted. Add the flour, salt and black pepper to the butter and stir to combine. Add the milk a little at a time and whisk the flour mixture into the milk each time until smooth. Add 1 ½ ounces of the shredded cheese. Whisk together and then whisk on and off for 1-3 minutes until smooth and thickened and remove from heat.

*Place the broccoli florets in a microwave-safe bowl and cover the bowl with a damp paper towel. Microwave for 2 minutes on high. (*You can otherwise steam the broccoli florets if preferred)

On a clean, dry cutting board sprinkle a small amount of flour to prevent sticking and lay down your sheet of defrosted puff pastry. Using a rolling pin, roll the pastry into a 10”x14” rectangle of even thickness. Using a knife (or a pizza cutter works wonderfully for this!), cut the dough into 6 equal pieces (2 sections lengthwise and 3 widthwise). Place the pastry sections a little bit apart on your parchment lined baking sheet.

Pour one tablespoon of cheese sauce in the center of each pastry square and spread across the center, leaving the four corners of the square bare (see photo above for details – you basically want the filling to be in a diamond shape in your pastry square, like another square that has been tilted so that the filling corners point to the flat sides of the pastry square). Divide the steamed broccoli and chopped chicken amongst the pastries and place on top of the cheese sauce. Drizzle the remaining cheese sauce evenly over the chicken and broccoli on each pastry square and then sprinkle the remaining shredded cheese on top. Fold the four corners of each pastry square over top of the filling (they do not need to meet).

In a small dish, combine the egg and tablespoon of water and whisk together to form an egg wash. Use a pastry brush to brush the egg wash over the top of the pastries. Place the baking sheet with the pastries into the fridge (or freezer) for 10 minutes to chill (puff pastry puffs better when it goes into the oven cold).

Transfer the baking sheet into the preheated oven and bake for 20 minutes until the pastry is golden and puffy. Serve warm.