Portobello and Flank Steak over Greens

Ingredients

• 0.5 cup balsamic vinegar 
• 0.5 teaspoon pepper black freshly ground
• 1 cup cherry tomatoes halved
• 1.5 pound flank steak trimmed
• 2  garlic cloves minced
• 0.5 teaspoon kosher salt 
• 6 cups salad greens mixed
• 0.3 cup olive oil 
• 6 large portobello mushroom caps 
• 1 large onion red cut into 1/2-inch-thick slices
• 1 tablespoon worcestershire sauce 

Equipment

• bowl
• whisk
• grill
• ziploc bags

Directions

1. Combine first 6 ingredients in a small bowl, stirring with a whisk until blended.
2. Combine steak, mushrooms, and onion in a large zip-top plastic bag.
3. Add 1/2 cup vinegar mixture to bag; seal. Marinate in refrigerator 2 1/2 hours, turning occasionally. Reserve remaining 6 tablespoons vinegar mixture.
4. . Prepare grill.
5. Remove steak and onion from bag, and place on grill rack coated with cooking spray. Grill 6 to 8 minutes on each side or until steak is desired degree of doneness and onion is tender.
6. Remove mushrooms from bag; discard marinade.
7. Place mushrooms on grill rack; grill 4 to 5 minutes on each side or until tender.
8. Cut mushrooms into 1/2-inch-thick slices.
9. Let steak stand 5 minutes.
10. Cut steak diagonally across grain into thin slices.
11. . Chop onion; combine onion and mushrooms in a medium bowl.
12. Combine mixed greens and tomatoes, and arrange evenly on plates. Top evenly with mushroom mixture. Arrange steak evenly over mushroom mixture; drizzle each serving evenly with reserved vinegar mixture.
13. Serve immediately.