350 g (12 oz) boneless cooked chicken, cut into bite-sized pieces
50 g (2 oz) margarine or butter
1 onion, chopped
1 cooking apple, peeled, quartered and sliced
2 teaspoons curry powder
25 g (1 oz) plain flour
300 ml (1/2 pint) chicken stock
100 g (4 oz) mushrooms, sliced
salt and freshly ground black pepper
3 tomatoes, skinned and roughly chopped
215 g (7 1/2 oz) frozen puff pastry, defrosted
beaten egg, to glaze