Melt butter with oil in large pan, saute chicken until golden. Add tomatopuree and saute for another minute. Add all vegetables and herbs and saute this too. Add stock and port, put a lid on the pan and leave to simmer for about 90 mins, until the meat falls from the bones.

Take the pieces of chicken from the pan, leave to cool. When cool pull meat from bones. Remove bayleaf and puree vegetables, if you like add the fishsauce and mix well. Heat up pan and add chicken.

Serve with mashed potatos.