Flank steak can be a challenging piece of beef to work up well. It's cheap and flavorful so it's worth the effort but it's best in low and slow cooking methods, except when flash grilling to a medium rare for fajitas. My mother made Swiss steak often with it when I was growing up, simmering it for hours in an onion, celery, bell pepper tomato sauce and serving over rice or mashed potatoes. Talking about it now makes me crave it so that's definitely on the menu for next week!
Another favorite preparation is Beef Braciole, or stuffed, rolled flank steak. The traditional Italian stuffing is bread crumbs flavored with garlic, onion, and parsley, although stuffed with strips of sweet pepper, onions, and garlic, is another personal favorite.
The key to flank steak is in preparing the cut itself. The extra time spent removing the prevalent silverskin and pounding that sucker out thin can make the difference between a really "Wow!" dish and a mediocre one. Everything else is embellishment. Don't let the number of steps being intimidating if you've never made this dish before. Once you've done it once, the second and many times after will feel easy.