Ahi Tuna and Cucumber Sandwiches with Tapenade

Fish, olives and olive oil offer a bonanza of heart-healthy fats. Whole grains and greens add plenty of fiber. Ahi, the Hawaiian name for yellowfin tuna, tastes best when cooked rare and then thinly sliced. If you prefer ahi cooked through, increase the time by seconds, not minutes, as it cooks quickly. If you overcook it, the delicate texture will be lost.