Cook the noodles following the pack instructions then rinse under cold water and drain thoroughly.
In a small saucepan melt together the peanut butter, coconut milk, sweet chili sauce and half the scallions, adding 1-2 tbs water to loosen the mixture to a drizzling consistency.
Mix the noodles, cucumber and beansprouts in a serving dish. Top with the shrimp, drizzle over the peanut sauce and scatter over the remaining scallions.