Heat grill pan over medium-high heat. Coat pan with cooking spray. Add steak to pan; grill 6 minutes on each side or until desired degree of doneness. Place steak on a cutting board; let stand 5 minutes.
Cut steak diagonally across grain into thin slices. Mix lime juice, olive oil and garlic and drizzle over steak; sprinkle with salt.
Heat tortillas on grill pan coated with cooking spray 20 seconds on each side or until lightly charred.
Heat scallions on grill until lightly charred.
Divide steak among tortillas.
Top with romaine, red cabbage, avocado and pickled red onions.
