thats interesting. the bir chef i know, showed me quite a lot of that adding water and reducing down technique. he used it with great effect with lots of dd spice mix and chilly powder + chicken bones and chicken, green chillies, cardomaon, cloves, bay leaf, covered in water and boiled right down. produced a really tasty quick easy curry. he called it "staff curry". apparently its part of learning to do a vindaloo.