For the dressing, heat the sesame oil, vegetable oil and chilli flakes in a small saucepan for 2-3 minutes until the flakes start to sizzle. Remove the pan from the heat and stir in the agave syrup first, then the soy sauce with a whisk.
Now bring the pasta water to the boil on the already warm stove and cook the soba noodles for 4 minutes.
Meanwhile, cut the spring onions into slices, chop the coriander and put both in a large bowl. Drain the pasta, rinse with clear water and also add to the bowl. Stir in the dressing and serve the pasta salad immediately.