2 6-inch lemongrass stalks
2 1/2 cups unsweetened coconut milk
4-inch piece fresh ginger, peeled and thinly sliced
1 1/2 pounds medium white potatoes, such as Katahdins or Long Whites, scrubbed
2 tablespoons peanut or other vegetable oil
2 medium onions, finely chopped
4 medium carrots, thinly sliced
1 serrano chile, seeded and minced
4 fresh kaffir lime leaves
1 teaspoon lemon juice
1/2 teaspoon salt
Trim the lemongrass and bruise with the back of a knife or the bottom of a saucepan. Bring the coconut milk, lemongrass, and ginger to a simmer in a large pot set over medium heat.
Cover,reduce the heat to low, and cook for 15 minutes. Meanwhile, peel and quarter the potatoes.
Discard the lemongrass and ginger, then add the potatoes to the coconut milk. Cover and simmer for 10 more minutes.
Transfer the potatoes with a slotted spoon to a large bowl; set aside, reserving
the coconut milk.
Heat a large saucepan or sauté pan over medium heat. Swirl in the oil, then add the onions and carrots.
Cook just until the onions are translucent,about a minute, stirring frequently. Add the chile and kaffir lime leaves. Reduce the heat to very low and continue cooking for 7 minutes, stirring often, until the onions turn golden.
Add the cooked potatoes. Stir the mixture, carefully breaking the potatoes into large chunks, but do not mash them. Cook for 2 minutes, until heated through.
Add the coconut milk to the pan. Stir in the lemon juice and salt; cook for 2 minutes. Discard the kaffir lime leaves and serve.
Source: The Ultimate Potato Book