Prepare your cilantro roots by washing them and scraping the outer skin and rootlets away from the main tap root. Slice the garlic into smaller pieces. Place the prepared cilantro roots and garlic in a mortar and pestle and pound into a smooth paste.
Next slice the Thai chilis into smaller pieces. Add them into the mortar and pestle, and pound until they are incorporated into the paste.
Add the fish sauce, lime juice, and palm sugar to your mortar and stir with the pestle until the palm sugar is dissolved and a homogeneous sauce has been formed. Taste and adjust the seasonings according to your personal preferences.
Before serving, top with fresh cilantro leaves. Enjoy with your next seafood dish, whether it be steamed crab or grilled lobster!
Notes
If you'd like the dipping sauce to be red, you can use red Thai chilis instead of green Thai chilis.
This dipping sauce is bold and flavorful. If it's too potent for you, feel free to add a tablespoon or so of water to make a more mellow dipping sauce.