we made a lot of brown bread-and-butter sandwiches with watercress and smoked salmon , and added some sort of christmasy things like elvas plums and chocolates-a stupid idea : no one ate any of them-and , by the time we had spread the whole lot out on a door taken off its hinges and covered with a gleaming tablecloth to make it seem like a buffet , it looked like a real grown-up feast .