Cook the linguine in a pot of boiling, salted water for 6-8 minutes. Drain and set aside. Meanwhile place the clams in a large bowl, cover with cold water and leave to soak for 10 minutes. Drain and set aside.
Heat the olive oil and dark sesame oil in a large pan over a medium heat. Add the garlic, chilli and shallots and cook for 3-4 minutes, being careful not to burn the garlic. Turn the heat to high and add the clams, sake, mirin, ginger and dashi powder. Cover the pan and cook, shaking occasionally every 2-3 minutes or until all the clams have opened. Sprinkle over the parsley and remove from the heat.
Stir the linguine through the clams to warm. Serve in large bowls with sourdough bread and a green salad.