The Italians and the Spanish are past masters at preserving food, either under oil, floating in brine, cured, pickled or packed in salt. With a quick visit to a good deli like ours, you can stock up on foods for impromptu feasts, especially if you stash a couple of loaves of bread in the freezer. Just arrange the contents of the jars and packets on a platter and drizzle with great olive oil, adding some fresh rocket.