In a medium bowl, whisk together balsamic vinegar, Worcestershire sauce, olive oil, Dijon mustard, garlic powder, and salt. Place the sirloin steak into a ziplock bag and pour the marinade over, ensuring it's fully coated. Seal the bag and refrigerate for at least 30 minutes.

While the steak marinates, finely chop fresh basil and parsley. In a small bowl, combine the herbs with lemon zest and a pinch of salt.

Preheat your grill to medium-high heat, around 400°F (200°C). Brush corn on the cob with olive oil and season lightly with salt and pepper. Grill for 10-12 minutes, turning occasionally.

Remove the steak from the fridge and let it sit at room temperature for about 10 minutes. Grill the steak for 4-5 minutes on each side for medium-rare, then let it rest for 5 minutes before slicing.

In a large bowl, toss together mixed spring greens, endive lettuce, halved cherry tomatoes, sliced red onion, and Gorgonzola cheese. Add the grilled corn kernels and half of the prepared gremolata. Drizzle with some vinaigrette and toss.

Plate the salad and lay the sliced steak on top. Drizzle with the remaining gremolata and vinaigrette.