Just combine all the ingredients and adjust to taste as needed. Be careful when handling the chilies; do not touch your eyes or any sensitive area of your body after using them…Yowza! Just pour the sauce over the prawns and cover and refrigerate. If you are cooking the prawns, do not overcook! The lime juice in the sauce will "cook" them some more if they are sitting long enough. I have made this up to the day before without a problem. You might want to add the cilantro before serving for a more attractive presentation.
Recipe by Have You Eaten, SF? at https://haveyoueatensf.com/thai-dinner-party/