Grilled Flank Steak With Horseradish Sauce

Ingredients

2 lbs flank steaks
1 small onion, diced,
3 garlic cloves, minced,
12 cup olive oil
14 cup white wine vinegar
2 tablespoons Worcestershire sauce
2 teaspoons sugar
1 teaspoon salt
1 teaspoon pepper, ground, fresh
1 cup sour cream
3 -4 tablespoons prepared horseradish
2 tablespoons white wine vinegar
1 tablespoon mayonnaise
1 tablespoon parsley, chopped, fresh,
12 teaspoon salt
12 teaspoon pepper
6 cups salad greens

Directions

Marinade: Stir together onion and remaining ingredients.
Fresh lemon juice can be substituted for vinegar.
Place steak in a heavy-duty zip-lock bag and add the marinade.
Seal bag and chill 8 hours, turning occasionally.
Remove steak from marinade and grill, covered with grill lid over medium-high heat 8 to 10 minutes each side or to desired degree of doneness.
Cut steak diagonally across the grain into thin strips.
Serve over salad greens with Horseradish sauce.
Horseradish Sauce: Mix together sour cream and remaining ingredients.