Cut the chicken into pieces, leaving the bone in. If you prefer boneless chicken, then debone the chicken.
Heat a deep pot and add the oil. Sauté the sliced shallots until aromatic or lightly browned.
Add the curry paste to the pot and stir until fragrant.
Add the chicken and lemongrass, stirring for 1 minute before adding the water.
Cover the pot and reduce the heat to medium. Bring the curry chicken to a boil, then lower the heat.
Add the potatoes and simmer for about 20 minutes, or until the chicken becomes tender.
Add the coconut milk and bring it to a boil. Serve hot.
Alternatively, you can let the chicken sit overnight before adding the coconut milk the next day.