Rice crackers, khao tang, are the traditional (and the best-tasting) vehicle for this creamy, flavorful dip. Together, they form this old-school dish that is still very much in demand, even though the city is flooded with all kinds of modern appetizers these days. The dip looks reddish but is not—should not be—hot. The color comes from river prawn tomalley, which also contributes extra creaminess and flavor.
- In a mortar, grind together the chiles, peppercorns, cilantro roots, and garlic to a smooth paste. Transfer the paste to a 2-quart saucepan and add the coconut cream and tomalley. Place the pan over medium-high heat and stir constantly for 1 minute. Stir in the shallots, coconut milk, pork, shrimp, sugar, tamarind, and salt and adjust the heat to maintain a gentle boil. Cook, breaking up the pork and shrimp with the blunt end of a wooden spatula into fine crumbles, until they are opaque, 6 to 8 minutes. Taste for seasoning and adjust as needed; you want it to be salty first, then sweet, and finally ever so slightly tangy (keep in mind that you'll eat this with unseasoned rice crackers). Once the taste suits you, stir in the peanuts. Remove from the heat and let cool until just slightly warmer than room temperature.
- Transfer the dip to a bowl and garnish with the coconut cream, red chile slivers, and cilantro leaves. Place the bowl on a large platter and arrange the rice crackers around it. Serve immediately.