Soak the porcini mushrooms in 150 ml (1/4 pint) boiling water for 10 minutes.
Cut the puff pastry into 4 diamond shapes and make 3 small incisions in the top. Place on a baking sheet, brush with beaten egg and cook in a preheated oven, 200°C (400°F), Gas Mark 6, for 12–15 minutes until golden and puffed.
Meanwhile, make large slits in the side of each chicken breast. Cut the pâté into 4 slices and put a slice inside each chicken breast. Divide the mushrooms in half. Put a quarter of one half inside each chicken breast and tie with string. Heat the butter in a large frying pan and cook the chicken breasts over a high heat for 5 minutes on each side until golden.
Pour in the white wine and remaining mushrooms and bring to the boil. Reduce the heat, turn over the chicken breasts, cover and simmer for 5 minutes. Remove the chicken from the pan and place on 4 warmed serving plates. Add the cream to the pan, heat for 1 minute and spoon over the chicken. Place a pastry top on each and garnish with chopped parsley.