Watercress can spark up you salad and possibly protect you against cancer.  Studies show that eating the veggie daily lowered DNA damage in healthy adults.  The veggie is crisp and peppery and you can add it to salads and sandwiches.  Don’t be shy with it.  By using it, you can increase your blood levels of the antioxidant lutein.  A restaurant I go to makes there Greek Salad with it, a good twist to an old favorite. Any more ideas?