Cook the bacon in a skillet until brown. Remove and then add the chicken thighs and also cook until brown. Then, set the chicken aside and cook the mushrooms.
Melt butter in the skillet and whisk in flour. Pour in cream and chicken stock and whisk until smooth. Stir in the chicken, bacon and mushrooms.
Add the cheese to the warm cream mixture and stir to melt. Then, stir in the Worcestershire sauce and fresh herbs until combined.
Pour the cream mixture into a baking dish. Top with a sheet of thawed puff pastry and brush with egg. Bake until the puff pastry browns, and the cream bubbles on the side.
When only a cozy British pub comfort food will do, I hope you try this chicken-mushroom pie with puff pastry. It's the perfect decadent, hearty dinner.