Heat the vegetable oil in a large pot or Dutch oven over medium heat.
Add the curry paste to the pot and stir-fry for about 2 minutes to release the flavors.
Add the chicken pieces and cook until browned on all sides.
In the same pot, add the sliced onion, the potatoes, coconut milk, chicken broth, tamarind paste, palm sugar, fish sauce, cinnamon stick, and bay leaves. Stir well to combine.
Bring the mixture to a boil, then reduce the heat to low, cover, and simmer for about 45 minutes to 1 hour, or until the chicken is tender and the potatoes are cooked through.
Stir in the roasted peanuts and simmer for an additional 5 minutes.
Taste the curry and adjust the seasoning by adding more fish sauce, sugar, or tamarind paste if desired.
Remove the cinnamon stick and bay leaves before serving.
Garnish with fresh cilantro and serve hot with jasmine rice.