Preheat oven to 350°F.

In a saucepan, over medium heat, melt 6 tablespoons of butter. Add onions and cook until the onions become translucent.

Stir in flour, salt and pepper, once combined slowly stir in the broth.

Add cream and continue cooking over medium heat until it becomes thick.

Add the chicken and vegetables. remove from heat and pour into a 9x13 baking dish.

Using a rolling pin, roll puff pastry sheet to the size of the baking dish, 9x13. Cut into 12 squares.

Cover the chicken mixture with puff pastry, brush with the remaining melted butter.

Bake at 350°F, for 35 minutes or until it is golden brown.

Remove from oven and let sit for 5 minutes before serving.