Flank Steak with Horseradish Sauce

We're big fans of flank steak at our house.  I wish it wasn't so darn expensive.  I will have to watch the sales because I plan to try this.  I also love horseradish and will most likely use this sauce with other beef recipes  as well.

1lb. beef flank steak
3 tbsp. lemon juice
2 tbsp. Dijon mustard
2 tbsp. Worcestershire sauce
2 garlic cloves, minced
1/8 tsp. hot pepper sauce

Horseradish sauce
1/4 C. fat free mayonnaise
1/4 C. reduced fat sour cream
1 tbsp. Dijon mustard
2 green onions, finely chopped
2 tsp. prepared horseradish

Using a sharp knife, score the surface of the steak with shallow diagonal cuts at 1 inch intervals, making diamond shapes,  Repeat on the other side.  In a large resealable plastic bag, combine the next five ingredients.  Add steak.  Seal bag and turn to coat; refrigerate for 8 hours or overnight.  Combine the sauce ingredients in a small bowl.  Cover and refrigerate.

Drain and discard the marinade.  Grill steak over medium hot heat for 7 to 9 minutes on each side or until meat reaches desired doneness.  Thinly slice meat across the grain.  Serve with sauce.