1. Preheat grill to medium-high heat.
2. Place parsley, 1 1/2 tablespoons oil, oregano, vinegar, red pepper, 1 garlic clove, and green onion in a food processor; process until finely chopped. Rub 2 tablespoons parsley mixture evenly over steak; reserve remaining parsley mixture. Let steak stand at room temperature 15 minutes.
3. Sprinkle steak with salt and pepper. Place steak on grill rack coated with cooking spray. Grill, covered, 4 minutes on each side or until desired degree of doneness. Place steak on a cutting board; let stand 10 minutes. Cut across the grain into thin slices.
4. Brush both sides of bread slices with remaining 1 tablespoon oil; grill 2 minutes on each side or until toasted. Cut remaining garlic clove in half; rub cut sides of garlic over toasted bread. Serve toast with steak and reserved parsley mixture.