Preheat tabletop grill, grill pan, or outdoor grill to high.
Combine first 10 ingredients in a shallow dish. Coat flank steak in mixture and reserve 10 to 15 minutes.
Trim ends and 1 inch of tops off of the scallions. Drizzle extra-virgin olive oil over both the scallions and the shrimp and season with salt, pepper, and red pepper flakes. Grill scallions and shrimp 2 minutes on each side. Then remove and reserve.
Place meat on grill pan and cook 3 to 4 minutes on each side. Remove meat and let juices settle, about 5 minutes.
Combine greens and onions and parsley leaves on a large platter or individual plates. Cut scallions into 1-inch pieces, scatter over greens, and then evenly distribute the grilled shrimp over the greens.
Mix the lemon juice, tomato paste, and Worcestershire in a small bowl and whisk in the extra-virgin olive oil. Season the dressing with salt and pepper and drizzle it back and forth over the arranged greens and scallions and shrimp. Slice the steak very thinly against the grain on an angle with a sharp knife and arrange it over the salad.