Mutton Kala Bhuna. Natives of Chittagong (south Bangladesh) used to cover their fried dark and tendered beef dish using banana leaves and packed it for long tours on foot. The first major innovation that led to what is now known as Kala-bhuna was the use of special spices and the long frying technique. The dish was invented shortly as it was common for the people of the area around Chittagong to fry curried beef for an extended period in order to preserve it for a longer time. Kala bhuna can be made of both beef and mutton, This meat dish is cooked with various ingredients by adding them gradually.