Start by making the puffed rice. Heat the oil in a small saucepan until very hot. Don't walk away, hot oil is dangerous. Test the oil by dropping in a few grains of rice, if it's hot enough the rice will crackle and spit straight away. Once you're happy the oil is hot enough, add the rest of the rice and swirl the pan for 20-30 seconds until the crackling has died down. Drain the rice through a sieve (reserve the oil for another use), then spread out on paper towels to drain any excess oil. Sprinkle with a little salt.
To make the dressing, warm the rice vinegar, sugar and salt in a saucepan, stirring until the sugar and salt are dissolved. Turn off the heat and add the garlic, sesame oil and chilli flakes. Once the mixture has cooled, pour it into a small jar or sealable container, add the lime zest, juice and miso paste, then shake to combine.
Cook your rice stick noodles in boiling water for 3-5 minutes, until just cooked. Keep an eye on them and taste often - you don't want to overcook them.
Drain noodles and refresh under cold water, drain again then add to a large mixing bowl.
Remove skin and stone from the avocado then slice thinly.
Slice the cheeks (sides) from the mango, peel them, then slice thinly.
Add avocado, mango, sprouts, spring onion (scallion), coriander (cilantro) and cashews to the mixing bowl with the noodles. Pour over the dressing, then use your hands to gently mix everything together.
Scatter with puffed rice, then serve immediately.
Notes
Serves four as a meal, or more as a side dish.
If you can't find black rice, substitute with black sesame seeds to garnish (don't puff them), or leave it out altogether.
Use a ripe but firm mango and avocado so they're easy to peel and slice, and don't disintegrate in the salad.
The heat level of the dressing is mild, if you like it hot you could easily double the quantity of chilli flakes.