Step 1

In a large saucepan over medium, heat the oil until shimmering. Add the shallots and ginger; cook, stirring often, until lightly browned, 3 to 5 minutes. Add the curry powder and cook, stirring, until fragrant, about 30 seconds. Add the chicken, potatoes, fish sauce and ½ teaspoon pepper; scrape up any browned bits.

Step 2

Stir in the coconut milk and 1 cup water. Bring to a simmer over medium-high, then cover partially, reduce to medium and cook, stirring occasionally, until a skewer inserted into the potatoes and chicken meets no resistance, about 30 minutes; the curry will be only lightly thickened. Off heat, stir in the lime zest, juice and cilantro, then taste and season with salt and pepper.