Cut off the tough parts of the stems by cutting across the whole bunch with a sharp knife. Separate the leaves, drop them into a basin of tepid water and swish them around to remove any dirt. Lift out the leaves (dirt and grit will remain in the bottom of the basin) and shake or spin them dry. Arugula is often quite sandy and may require several washings.
Add arugula to mixed green salads, or spotlight the leaves in a salad that features fruit such as pears or oranges; the peppery, pungent flavor of arugula complements the sweetness of the fruit. Add arugula leaves to sandwiches in place of other, less flavorful greens. You can also sautי arugula in olive oil with some chopped garlic; serve as a side dish or toss with hot pasta.