Open-Faced Beef Sandwiches With Greens and Horseradish Cream

From Cooking Light October 2008. This recipe calls for Texas toast. A 1.4 ounce slice of Italian or French bread may be substituted.

• Ready In: 40 mins
• Serves: 4
• Yields: 4 open faced sandwiches

Ingredients

• Horseradish Cream

• 2 1⁄2 tablespoons  prepared horseradish, drained
• 2  tablespoons light sour cream
• 2  tablespoons creme fraiche

• Sandwich

•  cooking spray
• 3 1⁄2 cups onions, vertically sliced (about 2 large)
• 1⁄2 teaspoon kosher salt, divided
• 1  lb  flank steak, trimmed
• 1⁄4 teaspoon black pepper, freshly ground
• 2  cups arugula, trimmed
• 2  teaspoons extra virgin olive oil
• 1  teaspoon  balsamic vinegar
• 4  slices  Texas toast thick bread, lightly toasted (1 1/2 ounce slice)

Directions

1. To prepare cream, combine horseradish, sour cream, and creme fraiche in a small bowl; cover and chill.
2. Preheat broiler.
3. To prepare sandwich, heat a large nonstick skillet over medium heat. Coat pan with cooking spray. Add onion and 1/8 tsp salt to pan; cover and cook 10 minutes, stirring frequently. Uncover and cook 10 minutes or until onion is golden brown.
4. Sprinkle steak with 1/8 tsp salt and pepper. Place steak on a broiler pan coated with cooking spray; broil 5 minutes on each side or until desired degree of doneness. Let stand 5 minutes. Cut steak diagonally across the grain into thin slices. Combine steak and remaining 1/4 tsp salt in a bowl, and toss to coat.
5. Combine arugula, oil, and vinegar in a medium bowl; toss gently. Spread 2 tablespoons horseradish cream over each bread slice; top each with about 1/3 cup onion, 1/2 cup arugula mixture, and 3 ounces of steak.