Flank Steak with Caramelized Onions and Balsamic Glaze

Ingredients

2/3  cup  balsamic vinegar

1  tablespoon  olive oil

6  cups  vertically sliced onion (about 1 1/2 pounds)

1/2  teaspoon  salt, divided

1  (1-pound) flank steak, trimmed

1/4  teaspoon  freshly ground black pepper

1/4  teaspoon  dried thyme

Cooking spray

Bring balsamic vinegar to a boil in a small, heavy saucepan. Reduce heat to medium; cook until reduced to 1/4 cup (about 5 minutes). Remove from heat.

Heat oil in a large nonstick skillet over medium-high heat. Add onion, and sauté 10 minutes or until tender. Sprinkle with 1/4 teaspoon salt; sauté 18 minutes or until onions are golden brown. Remove from heat.

Preheat broiler.

Sprinkle steak with remaining 1/4 teaspoon salt, pepper, and thyme. Place steak on a broiler pan coated with cooking spray; broil 6 minutes on each side or until desired degree of doneness. Cutsteak diagonally across grain into thin slices. Serve steak over onions; drizzle with balsamic glaze.