Cook the noodles to packet instructions (usually in boiling water for 5 minutes, depending on brand)
In a mixing bowl, mix the tahini, half the lime juice, maple, spring onions and cold water together.
Loosen with the cold water (start with 100ml) and season with a little salt and pepper.
When the noodles are cooked, lift the noodles out with tongs and place into the sauce along with the black beans.
Mix, you may need a little extra cold water to stop the tahini seizing up.
Taste for seasoning.
Cut the remaining half lime into two.
Serve between two bowls, garnishing with the lime, cucumber and chilli oil.
