Railway Lamb/Mutton curry

Railway Lamb / Mutton Curry dates back to the days of the British Raj, when traveling by train was considered aristocratic. This very popular and slightly spicy dish was served in Railway Refreshment Rooms and on long distance trains, with Bread or Dinner Rolls. The curry was not too spicy keeping in mind the delicate palates of the British. It was also popular with the Railway staff who had to be on duty for long periods at a stretch. The vinegar or Tamarind juice used in its preparation would ensure that the curry would last for quite a few days and was an ideal accompaniment with rice as well.
I remember my great grandfather making this curry using ghee, he learnt it from some of his colleagues.
I found this recipe in my grand mom's recipe book a few years back.