1 medium onion
3/4 cup white wine OR chicken broth
1/4 cup white-wine vinegar
2 Tblsp. olive or vegetable oil
1 tsp. dried basil OR 1 Tblsp. fresh basil
1/2 tsp. salt
crushed hot red pepper flakes
1 (1 1/2-lb.) flank steak, trimmed
1 clove garlic, halved
Thinly slice onion. Combine onion wine, vinegar, oil, basil, salt and red pepper flakes in a shallow glass baking dish; mix well.
Make slits in steak. Rub both sides of steak evenly with garlic. Place steak in dish; turn to coat. Cover; marinate in refrigerator for 30 minutes.
Preheat grill. Remove steak from marinade; discard marinade in dish. Pat steak dry with paper towels.
Grill steak 4 inches from heat for about 6 minutes per side for medium. Let stand for 10 minutes before slicing.
