Pound together chiles, lemon grass, shallots, galangal, candlenuts and shrimp paste or grind in food processor or blender, adding 1 1/2 tablespoons oil. Stir in turmeric and coriander. Heat remaining oil in large saucepan. Add ground ingredients and fry gently, stirring frequently, 4-5 minutes. Add dried shrimp and fry 2 minutes. Remove thick coconut milk from top of unshaken can with ladle. Combine remaining milks. There should be 3 cups thinner coconut milk. Add thin coconut milk and reserved shrimp stock to fried mixture and bring to boil, stirring constantly. Add fish balls and simmer 5 minutes. Add thick coconut milk and salt and simmer until gravy thickens.