Kolkata-Style Kosha Mangsho (Bengali Slow-Cooked Mutton)

Kolkata-Style Kosha Mangsho (Bengali Slow-Cooked Mutton)

Ingredients

For Marination

  • Mutton (goat meat) – 1 kg

  • Curd – ½ cup

  • Ginger paste – 1 tbsp

  • Garlic paste – 2 tbsp

  • Turmeric powder – ½ tsp

  • Kashmiri red chilli powder – 1 tsp

  • Mustard oil – 2 tbsp

  • Salt – to taste

For Cooking

  • Mustard oil – 6–7 tbsp

  • Bay leaf – 2

  • Whole spices:

    • Dry red chilli – 2

    • Green cardamom – 4

    • Cloves – 4

    • Cinnamon – 1-inch

  • Onions – 4 large, thinly sliced

  • Tomato – 1 medium, chopped

  • Potato – 2, halved (optional but very Bengali!)

  • Ginger paste – 1½ tbsp

  • Garlic paste – 1½ tbsp

  • Coriander powder – 1 tbsp

  • Cumin powder – 1 tsp

  • Red chilli powder – 1–1.5 tsp

  • Garam masala – 1 tsp

  • Sugar – 1 tsp (for caramelisation)

  • Salt – as needed

  • Warm water – as required

    Instructions

    1. Marinate the mutton (very important!)

    Mix mutton with curd, ginger–garlic paste, turmeric, chilli powder, mustard oil, and salt.
    Marinate for at least 2 hours (overnight is best).

    2. Fry the potatoes (optional)

    Heat mustard oil, fry the halved potatoes till golden.
    Remove and keep aside.

    3. Start the kosha

    In the same oil, add sugar and let it caramelise slightly — this gives the kosha its rich dark colour.

    Add bay leaf, dry chilli, cardamom, cloves, cinnamon.

    Add sliced onions and fry until deep brown.

    4. Add ginger–garlic

    Add ginger paste and garlic paste.
    Sauté until the raw smell disappears.

    5. Add dry spices

    Add coriander powder, cumin powder, red chilli powder.
    Sauté with a splash of water to prevent burning.

    6. Add tomatoes

    Add chopped tomato; cook until it melts into the spices.

    7. Add marinated mutton

    Add the marinated mutton and start kosha-ing —
    Cook on medium flame for 30–40 minutes, stirring often until oil separates and the colour becomes dark.

    8. Add potatoes & slow cook

    Add the fried potatoes.
    Add warm water (not too much — kosha should be thick).
    Cover and slow cook for 45–60 minutes until mutton is soft and gravy is thick and clinging.

    9. Finish with garam masala

    Sprinkle garam masala, give a final 5-minute kosha.

    Oil should float on top and colour should be deep brown.

    🍽 Serve With

    • Luchi (best!)

    • Basanti Pulao

    • Steamed Rice

    • Paratha