In a small bowl, mix together all marinade ingredients.
Place flank steak in a flat dish baking dish and cover with the marinade.
Marinate in the fridge overnight to 24 hours. Turn the steak over in the morning so the opposite side gets a good marinating as well. This is only important if your steak is thicker and the marinade doesn't totally immerse it. Otherwise, you can just make more marinade.
Heat a grill to medium heat. Remove steak from marinade and reserve the marinade.
Pour marinade into a small saucepan and heat until simmering. Use as a sauce for serving.
Grill flank steak about 10-15 minutes to desired doneness (it will be more tender at medium or medium-well). Flip steak halfway through grilling.
Remove from grill and let rest on a serving platter 5 minutes.
To serve, slice steak against the grain. Drizzle with additional cooked marinade if desired.
BROCCOLI:
Heat oven to 425 degrees.
Combine oil, tamari, garlic and sesame seeds in large bowl.
Toss broccoli in oil mixture and sprinkle with salt and pepper.
Place on a baking sheet and roast 10-15 minutes, turning once halfway through roasting.