The dish is done when the lamb is very tender. This will take you somewhere in excess of an hour, depending on what cut of lamb you have. Just leave it until it's done!
 

 Step 6:

Here's the finished Rogan Josh dish. Note how it completely changed color during the stewing process.

I hope you like this dish, it's a really tasty thing. Serve it with boiled rice, or maybe some sort of bread maybe Naan or Chapati. A full-bodied red wine should go with this well.