Grease 5cm/2inch ramekins with non-stick cooking spray or brush with melted butter. You can add a disc of parchment paper to the bottom of each ramekin too if you prefer.
Cut the thawed puff pastry into squares then press each piece of pastry into a ramekin.
Note: I don't blind bake this quiche as that is more suited to homemade pie crust/shortcrust pastry. Just make sure to bake the quiches on the bottom rack of the oven to prevent soggy bottoms.
Add the grated cheese, chopped crispy bacon, sautéed spinach and cooked mushrooms.
Whisk the eggs, cream, salt and pepper together and pour the egg mixture into each ramekin.
Fold the pastry over the topping and brush with a a beaten egg.
Place the ramekins onto a sheet pan and place on the bottom rack of a preheated oven.
Allow to bake for 20-30 minutes or until the pastry is crisp and golden and the filling is set.
Remove from the oven and allow to cool for at least 30 minutes before serving.