How to Make It
In a medium saucepan, heat 1 tablespoon of the canola oil. Add the shrimp shells and cook over moderate heat, stirring constantly, until pink and fragrant, about 3 minutes. Add the coconut milk and simmer for 15 minutes. Strain the infused coconut milk into a heatproof measuring cup; discard the shrimp shells. Wipe out the saucepan.
Meanwhile, in a mortar or mini food processor, pound or pulse the garlic, cilantro roots and white peppercorns to a paste.
In the medium saucepan, heat the remaining 2 tablespoons of canola oil. Add the cilantro paste and cook over moderate heat, stirring constantly, until fragrant, 30 seconds. Add the ground pork, sugar, fish sauce and the infused coconut milk and cook, breaking up the pork, until no trace of pink remains, about 8 minutes. Stir in the chopped shrimp, shallot and peanuts and cook, stirring, until the shrimp is white, about 2 minutes. Remove from the heat. Stir in the cilantro leaves and minced chile and season with salt. Serve the dip warm, with rice cakes or pita chips.
Note: Toasted Asian rice cakes are available in the snacks section of Asian markets.