Combine soy sauce, brown sugar, olive oil and garlic together in a large closeable plastic bag. Add the steak, seal the bag and marinate for at least 2 hours or overnight in the refrigerator. Remove steak from bag; discard left over marinade, and place on a foil lined baking sheet. Place on the top shelf of the oven and broil for 4-5 minutes on each side. Or, grill until browned to desired doneness.