You know those days when you had no idea you were having people for dinner and then that phone call comes mid-afternoon? Well, this is the quickly assembled first course that can turn a plain roast chicken, or anything else you think you can stretch for four people without much effort, into a dinner party. And actually, whenever you have to cook without time for planning, I think a roast chicken is nearly always the main course you need: It's much easier to come up with frills for before and after and alongside than to construct a fancy dinner party dish last minute. This can be in dollops on crostini (and you can buy baby toasts ready-made for the purpose in an Italian deli) or eaten as a dip and it even serves as a rather intriguing, gorgeously hued sauce for plain grilled meats.