Whisk the light coconut milk and shrimp paste together in a bowl. Pour into a large pot with the onion, ginger, and pork; bring the mixture to a boil for 5 minutes. Add the prawns; reduce heat to medium, cover, and cook another 2 minutes. Add the green beans, calabash, and green chile pepper; cover again and continue cooking until the mixture is nearly dry, about 10 minutes. Stir the thick coconut milk into the mixture and continue cooking until nearly all the moisture is absorbed, about 5 minutes. Serve hot.