Preheat the grill to medium-high heat.
Rub the flank steak with olive oil, salt, and black pepper.
Grill the steak for about 5-7 minutes on each side for medium-rare, or until desired doneness.
Remove the steak from the grill and let it rest for 5 minutes before slicing.
While the steak is resting, grill the corn for about 10-12 minutes, turning occasionally until charred and tender.
Once cooled, cut the kernels off the cob.
In a large bowl, combine the mixed salad greens, cherry tomatoes, Gorgonzola cheese, red onion, and grilled corn.
Slice the rested steak thinly against the grain and add it to the salad.
Drizzle the balsamic vinaigrette over the salad and toss gently to combine.
Serve immediately.