Add the palm sugar and water to a pan over a medium heat.
Stir until the sugar dissolves and begins to bubble into a light caramel.
Add the coconut milk, light soy sauce, rice vinegar, garlic, banana shallot and white pepper.
Stir well and simmer gently until slightly thickened.
Toss cooked noodles and vegetables through the sauce until evenly coated and warmed through.
Finish with spring onion, red chilli, fresh coriander and lime zest and juice if using.