Sirloin steak tips are often sold as flap meat.
Adjust oven rack to middle position and heat oven to 350 degrees. Toss steak with 2 tablespoons Worcestershire, 2 teaspoons pepper, and ¾ teaspoon salt in bowl; set aside. Toss bread with ¼ cup oil, 2 teaspoons garlic, ¼ teaspoon pepper, and ¼ teaspoon salt on rimmed baking sheet. Bake until light golden, 16 to 18 minutes, stirring halfway through baking.
Meanwhile, heat 1 tablespoon oil in 12-inch nonstick skillet over medium-high heat until just smoking. Add steak and cook until browned on all sides and meat registers 120 to 125 degrees (for medium-rare), about 7 minutes. Transfer steak to large plate and tent with foil.
Whisk Parmesan, mayonnaise, lemon juice, remaining 1 tablespoon Worcestershire, remaining ½ teaspoon pepper, remaining ½ teaspoon salt, remaining 3 tablespoons oil, and remaining 1 teaspoon garlic together in large bowl. Add lettuce and croutons and toss to combine. Season with salt and pepper to taste. Slice steak and serve with salad, passing extra Parmesan separately.
