In a medium bowl, combine balsamic vinegar, Worcestershire sauce, extra virgin olive oil, Dijon mustard, garlic powder, coarse salt, and ground black pepper. Mix well to create your marinade. Place the sirloin steak inside a ziplock bag, pour the marinade over it, seal, and refrigerate for at least 30 minutes to enhance the flavors.

While the steak marinates, prepare your gremolata. In a small bowl, finely chop fresh basil and parsley, and mix in lemon zest and a pinch of salt. Set aside.

Preheat your grill to medium-high heat (about 400°F). Drizzle the corn with olive oil and lightly season with salt and pepper. Grill for about 10 minutes, turning occasionally.

After marinating, let the steak sit at room temperature for about 10 minutes. Grill the steak for 4-5 minutes on each side for rare to medium-rare doneness, then let it rest for 5 minutes before slicing thinly.

In a small bowl, whisk together balsamic vinegar, olive oil, and a pinch of salt and pepper to create vinaigrette. Adjust taste as needed.

In a large mixing bowl, add mixed spring greens, endive lettuce, halved cherry tomatoes, and thinly sliced red onion. Pour in half of the vinaigrette and half of the gremolata, and toss gently.

Arrange the sliced grilled steak on top of the salad and drizzle with remaining gremolata and vinaigrette.