In a large pestle and mortar, add garlic and chili (if using). Crush for a few seconds to release aromas.
Add cherry tomatoes, fish sauce, lime juice, and palm sugar syrup. Crush together for about 1 minute until well combined.
Add shredded papaya and carrot into the mortar. Toss with tongs or chopsticks to coat evenly in the sauce.
Alternatively, combine shredded papaya and carrot in a large mixing bowl, pour over the crushed sauce, and toss together.
Add cooked prawns and mix gently.
Garnish with roasted peanuts and serve immediately.