Aloo Mutton Kassa
Tender mutton and soft potatoes slow-cooked in a rich, spicy onion-ginger-garlic gravy. This Bengali classic, often called Kosha Mangsho, is a true labor of love, perfect for a special Sunday lunch.
For 4 servings
5 steps. 90 minutes total.
- 1
Step 1
- a.Marinate the Mutton
- b.In a large bowl, combine the mutton pieces, whisked curd, 1 tbsp ginger paste, 1 tbsp garlic paste, turmeric powder, and red chili powder.
- c.Mix thoroughly to ensure each piece of mutton is evenly coated.
- d.Cover the bowl and let it marinate for at least 1 hour at room temperature, or for best results, refrigerate for 4-6 hours.
- 2
Step 2
- a.Prepare the Base
- b.Heat mustard oil in a heavy-bottomed pot or kadai over medium-high heat until it just begins to smoke. This removes its pungent raw smell.
- c.Reduce heat to medium, carefully add the potato halves, and fry until they are golden brown on all sides. Remove with a slotted spoon and set aside.
- d.In the same oil, add the sugar. Allow it to melt and caramelize to a deep amber color. This step is crucial for the curry's signature dark hue.
- e.Immediately add the bay leaves, cinnamon stick, green cardamoms, and cloves. Sauté for 30-40 seconds until they become fragrant.
- 3
Step 3
- a.Sauté the Masala
- b.Add the sliced onions to the pot. Cook on medium heat, stirring frequently, until they turn a deep golden brown. This is a key flavor-building step and requires patience, taking about 15-20 minutes.
- c.Add the remaining 1 tbsp each of ginger and garlic paste. Sauté for 2 minutes until the raw aroma disappears.
- d.Stir in the tomato puree, cumin powder, coriander powder, Kashmiri red chili powder, and salt. Cook this masala, stirring occasionally, until the oil begins to separate at the edges, which takes about 8-10 minutes.
- 4
Step 4
- a.Perform the 'Kassa' (Slow Sauté)
- b.Add the marinated mutton to the pot. Increase the heat to high and sear the mutton for 5-7 minutes, stirring continuously to brown it on all sides.
- c.Reduce the heat to low, cover the pot with a tight-fitting lid, and let the mutton cook. This slow-cooking process, known as 'kassa' or 'bhuna', is where the magic happens.
- d.Uncover and stir every 8-10 minutes to prevent sticking. Continue this for 45-50 minutes. The mutton will release its own juices and fat, and the masala will become very thick and dark.
- 5
Step 5
- a.Simmer and Finish
- b.Add the fried potatoes back to the pot along with 480 ml (about 2 cups) of hot water. Stir everything well to combine.
- c.Bring the curry to a rolling boil, then reduce the heat to a gentle simmer. Cover and cook for another 20-25 minutes, or until the mutton is fork-tender and the gravy has reached your desired consistency.
- d.Turn off the heat. Stir in the garam masala powder and ghee. Add the slit green chilies for aroma.
- e.Let the curry rest, covered, for at least 15 minutes before serving. This allows the flavors to meld beautifully.
What to keep in mind.
6 tips from the recipe — small details that make a real difference to the final dish.
- 1For the most authentic flavor, use mustard oil and do not skip caramelizing the sugar.
- 2Patience is key. Properly browning the onions ('beresta') and slow-cooking the mutton ('kassa') are essential for developing the deep, rich flavor.
- 3Using bone-in mutton pieces adds significantly more depth and flavor to the gravy compared to boneless meat.
- 4Always add hot water to the curry. Adding cold water can cause the meat to toughen.
- 5This dish tastes even better the next day as the flavors mature and deepen overnight.
- 6If you're short on time, you can pressure cook the mutton for 4-5 whistles after the 'kassa' step, then add potatoes and simmer.
Adapt it for your goals.
Spicier Version
Increase the amount of red chili powder and add a few more slit green chilies along with the mutton to infuse more heat into the meat.
With ChickenWith Chicken
This recipe can be made with bone-in chicken pieces. Reduce the 'kassa' time to 20-25 minutes and the final simmering time accordingly, as chicken cooks much faster.
No Potato VersionNo Potato Version
Simply omit the potatoes for a pure 'Mutton Kassa' or 'Kosha Mangsho'. The gravy will be richer and more concentrated on the mutton flavor.
Pressure Cooker MethodPressure Cooker Method
After completing Step 4 (the 'kassa'), transfer everything to a pressure cooker. Add the potatoes and hot water, and cook for 5-6 whistles on medium heat. Let the pressure release naturally.
Why this is on our healthy list.
Excellent Source of Protein
Mutton is a high-quality protein source, crucial for building and repairing tissues, muscle development, and supporting overall body functions.
Rich in Iron
This dish provides a significant amount of heme iron from the mutton, which is easily absorbed by the body and helps in preventing iron-deficiency anemia and boosting energy levels.
Contains Essential Minerals
Mutton is also a good source of essential minerals like zinc, which supports the immune system, and phosphorus, which is vital for bone health.
Frequently asked questions
'Kassa' (or 'Kosha' in Bengali) is a slow-cooking technique. It involves sautéing the meat and spices over a low flame for an extended period, allowing the meat to cook in its own juices and the spices to release their full flavor, resulting in a thick, rich, and intensely flavorful gravy.