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
While the rice is cooking, cut the onion into thin wedges. Halve the carrot and zucchini lengthwise, then thinly slice on an angle. Trim the beans, then halve. Coarsely chop the coriander leaves, discarding the stems. Cut the fish into 2cm chunks.
Step 3 — Start stir-fry
Heat 2 tsp oil in a large deep frypan over high heat until hot. Stir-fry the onion and carrot for 2 mins or until starting to soften. Add the beans and stir-fry for 2-3 mins. Add the zucchini and stir-fry for 2-3 mins until the vegetables are just tender.
Step 4 — Coat fish and cook
Meanwhile, put the cornflour in a shallow dish and season with salt and pepper. Add the fish to the seasoned flour and gently toss to lightly coat. Heat 1 tbs oil in a medium frypan over high heat. Cook the fish, turning regularly, for 3-4 mins until golden and cooked through. Remove from the pan.
Step 5 — Finish stir-fry
Stir the oyster sauce and coriander into the vegetables. Add the fish and very gently stir until combined and heated through.
Step 6 — Flavour rice
Fluff the rice with a fork. Add the sesame oil and sesame seeds and stir to combine. Divide the rice and stir-fry among plates to serve.