For the steak: In a large, resealable plastic bag, mix the soy sauce, sesame oil, chiles and ginger. Add the steak to the marinade, seal the bag, and move the steak around to coat it with marinade. Marinate the steak in the refrigerator for at least 8 hours or ideally overnight.
For the bruschetta: In a medium bowl, toss the tomatoes with the sesame oil, olive oil, vinegar, basil, sesame seeds and salt. Set aside.
Remove the steak from the refrigerator 30 minutes prior to cooking; preheat a grill pan over high heat.
Oil the grill pan with the vegetable oil. Season the steak on both sides with the 1/2 teaspoon salt. Grill over high heat until nicely marked and cooked to the desired doneness, about 3 to 4 minutes per side for medium. Allow the steak to rest for 10 minutes before slicing on an angle, against the grain.
Serve topped with the marinated tomatoes.