Rinse the rice until the water runs clear. Put in a small saucepan with 250ml (1 cup) water, cover and bring to a simmer over medium heat. Reduce the heat to low and cook for 12 mins or until tender and the water is absorbed. Turn off the heat and stand, covered, for at least 5 mins.
Step 2 — Prep ingredients
Meanwhile, trim the beans and cut into short lengths. Halve the zucchini lengthwise and thinly slice on an angle. Peel and finely grate the ginger.
Step 3 — Make stir-fry sauce
Combine the ginger, oyster sauce, mirin, 1 tbs soy sauce, 3 tsp white vinegar and 1 tbs water in a bowl.
Step 4 — Stir-fry beef
Separate the beef stir-fry. Heat 1 tbs oil in a large deep frypan over high heat until very hot (beef stir-fry is best with hot and fast cooking, so get your pan very hot before adding the beef and stick to the short cooking time). Stir-fry the beef for 1-2 mins until browned. Remove from the pan.
Step 5 — Stir-fry vegetables
Heat 2 tsp oil in the same pan. Stir-fry the beans and zucchini for 1 min. Add the stir-fry sauce and cook, stirring, for 1 min or until the vegetables are just tender.
Step 6 — Get ready to serve
Add the beef and any resting juices to the vegetable stir-fry and cook, stirring, for 30 secs or until heated through. Fluff the rice with a fork. Divide the rice and stir-fry among bowls. Scatter with the sesame seeds to serve.