Spiralize the courgettes and the marrow. Toss them with a pinch of salt and place in a colander to release the water. Meanwhile finish spiralizing the carrots and turnips.
Stir fry all spiralized vegetables separately in some olive oil over a medium to low heat. Transfer to a colander when al dente.
For the sauce, blend all ingredients together to obtain a velvety texture. Season to taste with salt and pepper.
Transfer to a pan and warm the sauce before adding the veggie noodles. Add the chopped chilli and fresh herbs to decorate.
Notes
You can choose to use only 1 kind of vegetable. When using only courgettes or zucchini the dish is called zoodles.