In the small bowl of a food processor, blitz the tempeh and walnuts to a coarse rubble the size of peas or smaller.
Cook the rice noodles according to the packet instructions, then lift out, drain, rinse under the cold tap.
Coat with a tablespoon of the oil and put to one side.
Put a wide frying pan on a medium heat and, when hot, add the beansprouts and a splash of water.
Stir-fry for two minutes, then tip into a colander.
Put three tablespoons of rapeseed oil in the same wide frying pan and set it on a medium heat.
Once hot, add the garlic, fry for about two minutes, until crisp, then tip into a small heatproof bowl.
Stir the soy sauce, black vinegar, fish sauce, brown sugar and lime juice into the garlic bowl.
Put the remaining three tablespoons of oil in the same frying pan, keep the heat on medium and, when the oil is very hot, add three-quarters of the spring onions and cook, stirring, for two minutes.
Add the tempeh and walnut mixture and fry, stirring occasionally, for about 10 minutes, until it turns crumbly and golden.
Put the noodles in a large bowl, and top with the tempeh and walnut mixture, the beansprouts, the remaining raw spring onions, the chilli oil sediment and the coriander.
Pour on the dressing, toss well and serve.
