1/2 cup lemon juice
3/4 cup orange juice
1/4 cup honey
3/4 cup olive oil
1 cup port wine
1 (2 inch) piece fresh ginger, grated
5 cloves garlic, sliced
2 1/2 pounds flank steak
Whisk together the lemon juice, orange juice, honey, olive oil, port, ginger, and garlic in a large glass or ceramic bowl. Add the flank steak, and toss to evenly coat. Cover the bowl with plastic wrap, and marinate in the refrigerator 1 hour to overnight.
Preheat an outdoor grill for medium-high heat, and lightly oil the grate.
Cook the steaks until they are browned on the outside and red in the center, about 3 minutes per side. An instant-read thermometer inserted into the center should read 125 degrees F (52 degrees C). Slice the steak thinly across the grain before serving.