Ready in 45 minutes
1. Preheat the broiler. Place the flank steak ~~lthttp://recipes.prevention.com/RecipeSearch/flank%20steak-Recipes.aspx> on the rack of a broiler pan and coat all sides with the pepper and garlic. Let stand about 10 minutes.
2. Heat the oil in a large skillet over medium-high heat. Cook the onions for 8 minutes, or until lightly browned. Reduce the heat to medium-low and add the vinegar to deglaze. Stir in the broth, cover, and cook for 15 minutes, or until the onions are very soft and browned. Remove from the heat.
3. Prepare the pasta according to package directions, drain, and place in a large bowl.
4. Meanwhile, broil the steak, 4 inches from the heat, for 12 minutes, or until a thermometer inserted in the center registers 145F for medium rare, 160F for medium, or 165F for well done. Let stand for 10 minutes, then slice into thin strips.
5. Stir the arugula into the onions. Add the pasta and toss to coat. Add the steak strips and top with the cheese.