½ onion, diced
6 fresh shiitake mushrooms, diced
1 tbsp chopped fresh tarragon leaves
150ml/5fl oz chicken stock
sea salt and ground black pepper
½ tsp Chinese five-spice powder
1 tbsp rapeseed oil
1 tbsp Shaoxing rice wine
1 tbsp light soy sauce
150ml/5fl oz double cream
1 free-range egg
3 sheets puff pastry
300g/10½ oz chicken breasts
50g/1¾oz frozen peas