1. Heat the oil in a medium heavy saucepan over medium low-heat. Add the shallots, ginger, and garlic and cook, stirring often, until the shallots are golden, about 3 minutes. Add the curry powder and red pepper and stir until fragrant, about 15 seconds.

2. Whisk in the broth, peanut butter, coconut milk, lime juice, fish sauce, and brown sugar. Bring to a simmer and simmer over low heat to blend the flavors, about 3 minutes. Transfer to a bowl and let cool, then cover and refrigerate until chilled, at least 2 hours or up to 2 days (if the chilled dip is too thick, thin with water or broth).

3. Transfer to a serving bowl and sprinkle with the cilantro. Serve at room temperature.