Pour boiling water onto the noodles in a heat-proof bowl and leave to stand for 15 minutes (or cook according to packet instructions).
Once cool, strain the noodles and cut into 15cm/6in lengths and leave to drain.
Check the crab meat for pieces of shell, removing any pieces found, and put to one side.
Mix the peanut butter, garlic and mustard together.
Add the vinegar, soy, spring onions and oil.
Add the noodles and mix together well.
To serve, place the dressed noodles into bowls, sprinkle with crab meat and serve.
