Tip the rice into a bowl and cover with cold water. Set aside to soak.
Halve the butternut squash. Scoop out the seeds. Peel the squash and chop into chunks around 2cm across. Peel and grate the garlic and ginger. Halve the chilli. Finely chop it, flicking out the seeds for less heat. Halve or quarter the mushrooms, depending on how large they are.
Warm a wok or large pan over a medium heat for 1 min. Add ½ tbsp oil and the mushrooms. Stir and fry for 3 mins till the mushrooms start to brown.
Stir in the garlic, ginger and chilli. Add 1 tsp China 5 spice. Cook and stir for 1 min. Add the butternut squash. Drain the rice and add that too.
Pour in the tamari. Crumble in the stock cube. Pour in 400ml boiling water. Give everything a stir to mix it all together. Cover, turn up the heat and bring to the boil. When it’s boiling, turn the heat down and simmer for 30 mins till the squash and rice are both tender.
While the squash simmers, tip the cashews into a dry frying pan. Toast over a medium heat, shaking the pan now and then, for 2-3 mins till the nuts are golden.
Tip the cashews out onto a board. Let them cool for a few mins, then roughly chop them.
When the butternut squash and rice are tender, ladle the braise into warm bowls. Top with the chopped cashews and the coriander leaves to serve.