First thing in the morning, prepare and marinate the steak. Place a double layer of aluminum foil — about 24 inches (60 cm) — on the counter. Place the steak in the middle.
In a small bowl, whisk together olive oil, balsamic vinegar, sugar, paprika, Dijon mustard, dried basil, dried oregano, salt, and black pepper.
Pour half the marinade on the steak and spread it evenly. Turn the steak and spread the other side with the remaining marinade. Wrap tightly in the foil (this keeps marinade on both sides) and place in the refrigerator to marinate for the day (overnight marinating is okay, too).
About an hour before serving, remove steak from the refrigerator and bring to room temperature.
Heat your grill (charcoal or gas, or you can use a cast iron pan on the stovetop).
About 12 minutes before serving, unwrap the steak and grill 3 minutes on one side, and 2 1/2 minutes on the other for medium rare.
Place cooked steak on a cutting board, cover, and let sit 5 minutes.
To serve, prepare the sauce by heating the Worcestershire sauce and butter together until sizzling. Set aside.
Slice the focaccia or rolls.
Slice the steak. (see note)
Divide the sliced meat among the focaccia/rolls and top with a drizzle of the sauce.
Serve with a green salad.