Turn oven to Broil on high.
In a medium bowl, whisk together marinade ingredients: vinegar, olive oil, Worcestershire sauce, garlic, pepper, red pepper and salt. Dip flank steak and allow it to absorb the marinade on both sides. Place steak int he center of a baking sheet.(Another option: Transfer to a large ziplock bag if desired and place steak in to allow to coat.)
Toss the broccoli in remaining marinade and place evenly around the steak. ( I also like to sprinkle a little bit of garlic powder on my broccoli but this is not necessary.)
Broil for about 5 minutes, remove the pan and flip the steak. Broil for approximately 5 more minutes or until cooked to your desired level. Remove for the oven and allow to rest for about 5 minutes before cutting. Slice steaks against the grain of the meat and enjoy with your broccoli and rice or desired side dish!