Sometimes, you just have to eat steak. Flank steak is packed with protein (23 grams for every 3 ounces of meat), and easy to prepare -- you don't even need to gas up your outdoor grill.
Here's a recipe for marinated flank steak lifted directly from Alton Brown's "I'm Just Here for the Food":
1 cup chopped yellow onion
4 cloves minced garlic
1/3 cup white wine
1/4 cup soy sauce
1 tablespoon honey
1 tablespoon extra-virgin olive oil
1 teaspoon Worcestershire sauce
1/2 teaspoon fresh minced ginger
1/4 teaspoon freshly ground black pepper
1 flank steak
First, make the marinade: Process all the above ingredients (except the steak -- duh) in a food processor until the onions are pureed, pour the contents into a gallon plastic zip-top plastic freezer bag with the raw flank steak, and squeeze out as much of the air as possible before sealing the bag. Refrigerate it for 12 to 24 hours.
When you're ready to eat, adjust the rack in your oven so that the meat'll be about 2 inches from the broiler element, preheat your broiler (set it on high), place the now-marinated flank steak on a broiler pan, and cook it for 3 minutes per side for rare / 4 minutes per side for medium. Let it rest for 5 minutes, and then slice it thinly on an angle. Done and done.