Heat oven to broil.
Whisk together with garlic.
Dijon mustard, Worcestershire sauce, ground mustard, sea salt, and pepper.
Line a broiler pan with foil and place steak on top.
Coat evenly with mustard mixture and let stand 10 minutes.
Broil steak to desired internal temperature. (rare, done, well done, etc) (Four minutes per side for medium-rare)
Let stand 5 minutes before slicing and serving.
For a Step 1 version, eliminate Worcestershire Sauce and sub low-sodium soy sauce.
Source: South Beach Diet