Method of Preparation :
Soak rajma overnight. Roast the ingredients for the masala and grind it to a fine powder. Keep aside.
Marinate mince meat with salt, 1tsp chilli powder, 1/4tsp turmeric, ginger-garlic paste and vinegar for 1 hour. Pressure cook both the rajma and mince meat together with 2-3cups of water for 15 minutes.
Heat oil in a pan and saute onion paste till golden colour over a medium flame. Add the remaining chilli powder, turmeric powder and tomatoes and sauté till tomatoes are amalgamated. Add cooked mince, coriander paste, ground masala and bring to a boil. Cook till quite thick. Add butter and remove from fire.
Garnish with slit green chillies and lemon slices.