Blend the shallots, ginger, garlic, turmeric and cili boh in a blender and process till fine. Place the paste in a pot with the chicken, santan, water, tamarind paste and salt and bring to a boil. Add the lemongrass and kaffir lime leaves, then lower heat and simmer for 30 to 45 minutes.
Remove cooked chicken pieces from the pan and set aside. Continue cooking the gravy until thick, then add the chicken back into the pan with the brown sugar and kerisik and cook, stirring for 5 more minutes. Remove from heat and serve immediately.