1. Heat the oil in a wok or deep saucepan over high heat. Add the shallots, garlic, ginger, chile(s), and coriander and stir-fry until golden brown, about 3 minutes, stirring with a wooden spoon.

2. Stir in the coconut milk and bring to a boil. Stir in the peanut butter, soy sauce, lime juice, sugar, and black pepper, reduce the heat to medium, and let simmer until thick and richly flavored, about 5 minutes. Stir in the cilantro and cook for 1 minute. Taste for seasoning, adding soy sauce and/or lime juice as necessary. Serve at room temperature. The sauce can be refrigerated, covered, for up to 3 days. Let return to room temperature and stir to recombine before serving.