Start by cutting the green beans into 2–3cm pieces. Blanch in hot water for 4 minutes. Drain, run under cold water and leave to cool.
Peel the cucumbers and remove the central watery, seedy bit. Slice into thin strips. Pop into a large bowl.
Halve the tomatoes and scoop out the centre. Slice very thin and pop into the bowl.
Peel and thinly slice the carrot into strips, same as the cucumber, and add to the bowl.
Take the red onion, thinly slice and add to the bowl. Mix by hand.
Add the prawns and peanuts and mix through.
Now put the chillies in a mortar and crush them, followed by the garlic.
Add the brown sugar, lime juice and fish sauce and mix through.
Add the sauce to the salad and mix everything together.
Serve with a sprinkling of peanuts.
