Bring a large pan of salted water to the boil. Drop in the rice and let it lightly bubble for 10 minutes. Bring a kettle of water to the boil. Drain the rice into a colander that will fit into the saucepan. Pour a few inches of freshly boiled water into the bottom of the saucepan, put the colander with the rice into the pan over a low heat. Cover the colander and steam for 8 minutes.
While the rice is steaming, heat a wok or large frying pan. Add the sesame oil and let it warm then add the veg and soy sauce and a splash of water. Stir fry for a few minutes. Set aside.
Once the rice is cooked, fork through the butter if using, tip onto a serving platter and top with the veg and a sprinkle of chilli flakes