Combine balsamic vinegar, soy sauce, honey, olive oil, and crushed garlic in a large ziplock plastic freezer bag. Add steaks; seal bag. Turn to coat; let stand at room temperature for 30 minutes. Remove steaks; discard marinade.
Heat a grill pan over high; lightly coat with cooking spray. Add steaks; cook to desired degree of doneness, about 3 minutes per side. Transfer steaks to a cutting board; let stand 5 minutes. Cut across the grain into thin slices. Sprinkle with salt and pepper.
I used flank steak and marinated it for several hours. Will make again.