Preheat the oven to 220°C/200°C fan.
First make the potato noodles. Use a spiralizer set to the largest setting possible (if you have a choice) to make the noodles. Wrap them in a kitchen towel and squeeze to remove any excess moisture. Tip them onto a lined baking tray and drizzle with sesame oil. Sprinkle chilli flakes, salt and pepper and massage into the noodles. Place into the oven and roast for 15 minutes. Remove when ready.
Heat the garlic oil in a large frying pan. Add the ginger and toss briefly before adding the salmon and cooking for 3 minutes on each side. Remove from the pan and set aside.
Add the pak choi to the pan and as soon as it’s slightly wilted and charred, add the noodles and sauce and toss to coat. Use tongs to divide the noodles between two plates and serve the salmon fillet on top. Drizzle with any extra sauce and top with coriander leaves and chopped up chilli (if using).