Cook the pasta in salted water according to the instructions on the packet. Before draining, skim off a cup of the boiling water and set aside.
Finely chop the onion, garlic and ginger, cut the chilli into fine rings. Sweat together in a little oil. Add the prawns and crayfish and let them steep a little. Add the spring onions and stir in briefly. Now add the sambal oelek and sherry, deglaze with coconut milk. Add the tomato cubes, the sugar and the pasta water collected beforehand and simmer gently for approx. 5 minutes. Stir in coconut flakes and season with salt, pepper and lemon juice. If necessary, thicken with cornstarch dissolved in a dash of cold water.