Flank steak, an underused cut of beef, is mighty tasty.  It’s a real lean cut too, for those watching how much fat they eat.  The drawback to flank steak is that if you don’t know what you’re doing with them, they’re tough as leather.  The steak is a thin cut and the secret to cooking it is to cook it no more done than the rare side of medium, and to cut it into thin slices against the grain, or from the short side.  Get your slicing knife as close to level with the meat as possible and slice the meat about 1/8-inch thick at about a 160 degree angle.  It’ll be so good you’ll be tempted to hoot and holler, but don’t do it at the table.

Remove any bits of silverskin or membranes from the flank steak.  Salt and pepper both sides of the meat; place meat in a non-reactive baking dish and pour 1/3 cup of the Sweet Mango Pepper Sauce over it, coating both sides well.  Set meat aside at room temperature for one hour.

Light a gas char grill and heat to medium, or build a hardwood charcoal fire and let it burn down to the point where the coals are glowing red with a coating of white ash.  Combine the remaining Sweet Mango Pepper Sauce and butter in a saucepan over medium heat.  Cook, stirring often, just until the butter is melted; remove from heat.  Remove the flank steak from the baking dish and pat dry using absorbent paper towels.  Baste the meat liberally with the butter mixture and place on the grill.  Grill the meat, basting often with the butter mix, until reaches an internal temperature of about 135 degrees (medium-rare). Turn only once.  Remove from grill and set meat aside to rest for 10 minutes, covered loosely with foil.  Slice thin at about a 160 degree angle against the grain.  Drizzle the sliced meat with the remaining butter mixture and serve at once.