Heat oil in a large skillet over medium high heat. In a medium bowl combine the onions, chile peppers, candlenuts, shrimp paste, turmeric, ginger, galangal, lemon grass and mustard seed. Blend together with a little water to form a fine paste. Add to skillet and saute until fragrant and almost dry.Advertisement
Add 2 cups water and bring all to a boil. Add chicken and potatoes. Reduce heat and let simmer about 20 minutes, or until chicken is cooked (no longer pink inside) and curry is quite thick in consistency.
Add salt to taste. Remove from heat and add vinegar. Mix well and serve. This dish is best served with steamed white rice, as it is full of flavor.