Arugula is one of the most nutritious of salad greens, containing significant amounts of Beta-carotene, Vitamin C and Calcium. Arugula is a member of the mustard family, but with a mild spiciness rather than a bitter mustard taste. Substitute Arugula in sandwiches for lettuce, use as an "herb" to flavor dishes, or eat as a main salad ingredient. Arugula goes combines well with citrus fruits, berries, avocado and other milder lettuces. It is delicious served with dressing made with balsamic vinegar.