By Harold McGee
Rocket (or Italian arugula, both from the Latin root roc meaning “harsh, rough”) is the name given to several different plants and their leaves, all small, weedy cabbage relatives from the Mediterranean region that are especially pungent, with a full, almost meaty flavor built from various aldehydes, including almond-essence benzaldehyde. They’re frequently used to enliven a salad of mixed greens, but are also pureed into a brilliant green sauce or put on pizzas. Even the briefest cooking will inactivate their protection-generating enzymes and turn them into tame greens. Some large-leaved varieties are quite mild. Like rocket, the different forms of cress—water, garden, winter—are small-leaved and pungent, usually used as a garnish or as a refreshing counterpoint to a rich meat. Their South American relative, the window box nasturtium plant, sometimes lends its slightly pungent flower for a garnish; the more peppery flower buds are also used.