Warm a frying pan or wok over a medium heat. Toss in the cashews and toast for 2-3 mins till golden. Tip into a small bowl.
Zest and juice the lemon into a small bowl. Whisk in the tahini with 1 tbsp cold water. Finely slice the salad onions, trimming off the roots and top 1cm, and add those to the bowl. Set aside.
Slice the courgettes into 1cm-thick rounds. Halve the pepper and scoop out and discard the seeds. Roughly chop the pepper. Peel and trim the carrots. Thinly slice them on the diagonal. Peel and thickly slice the onion.
Heat the pan or wok you used to toast the cashews for 1 min. When warm, pour in 1 tbsp oil. Add the veg, season and stir fry for 5 mins till golden.
While the veg fry, cook the noodles. Put 2 bundles of noodles into a pan and cover with boiling water (see our tip below for what to do with your leftover bundle). Simmer for 3-4 mins till tender. Drain, tip back into the pan and immediately pour over the tahini sauce. Toss to mix. Pop a lid on the pan to keep the noodles warm.
Peel and grate the ginger and garlic. Whisk 1 tbsp sugar and 2 tbsp brown rice vinegar together. Add the grated garlic and ginger. Pour into the pan or wok with the veg, stir everything together and cook for 2 mins.
Taste and season the noodles and the veg. Divide the noodles between 2 plates. Top with the sticky veg. Scatter over the toasted cashews to serve.