Roast the Aromatics: In a dry pan over low heat, roast the dried chilies, shallots, and garlic until fragrant and slightly charred. This step is essential to achieve that authentic smoky flavor.
Pound the Paste: Using a mortar and pestle, pound the roasted chilies, shallots, and garlic until fine. Add the grilled shrimp paste and continue to pound until fully combined.
Incorporate the Shrimp: Add the ground dried shrimp to the mortar and mix until well integrated.
Fry the Paste: Heat a little vegetable oil in a pan over low heat. Add the pounded mixture and stir-fry until the fragrance is released.
Season: Stir in the palm sugar, tamarind concentrate, and fish sauce. Continue to cook on low heat, stirring constantly, until the ingredients meld together into a rich, dark-colored paste. (If it becomes too thick, add a splash of water).
Cool and Store: Once the flavor is balanced (sweet, savory, with a hint of tang), remove from heat. Allow the paste to cool completely before transferring to a clean, airtight container.