In a large bowl add the marinade ingredients and mix together well. Add the steak and leave to marinade for 15 minutes. Using a slotted spoon remove and put on the baking sheet, with space between each piece. Toss the broccoli in the marinade and add to the tray, between the steak pieces. Reserve the marinade and bake the tray for 10 minutes, or until the beef is cooked through and the broccoli is just tender.
Scatter with the spring onions, chilli and sesame seeds before serving.