Crush a handful of roasted unsalted peanuts to a coarse powder, using a mortar and pestle. Keep aside. Clean the mortar and pestle.
Take palm sugar in a small pan and melt it on low to medium flame. Add 2 tbsp of water. It should end up in a thick shiny syrup. That way it mixes easily with the salad.
Peel the papaya, shred it to thin bits and soak in cold water, during which you can prepare for the remaining salad. Soaking makes papaya crunchy.
Make 1-inch pieces of green beans. Don’t use the endings.
Crush peeled garlic and chilies lightly in mortar. Don’t crush them to fine paste. Some bits and pieces should be there. Add crushed peanuts to these and mix well.
Add shredded papaya and keep on pounding, but lightly, just enough to let the mixture get soaked into flavors.
Add the palm sugar syrup, beans, tomatoes, fish sauce and lime juice. Keep on pounding lightly. If you cannot hold the mixture into the mortar, shift it to another pot and pound part by part, till all of it is done. Your yummy Som Tam is ready!
Take it in a large dish and sprinkle it with crushed peanuts.