Boil Chicken: In a pot, add water, salt, 3-4 crushed garlic cloves with skin, chicken pieces, black cardamom pods, black peppercorns, and bay leaves. Boil for 7-8 minutes until chicken is half cooked. Strain and set aside.
Boil Cashew Nuts: In a pan, add water and cashew nuts. Boil for 3-4 minutes. Strain and set aside.
Boil Mushrooms: In a pot, add water, salt, and mushrooms. Boil for 2-3 minutes on high flame. Strain and set aside.
Prepare Cashew Paste: In a mixer grinder, blend boiled cashews and milk into a smooth paste. Set aside.
Cook Creamy Garlic Chicken: Heat oil in a kadhai. Add crushed garlic cloves and butter; sauté until garlic is translucent. Add a little water, crushed black cardamom, and cashew paste. Simmer on medium flame. Add butter, water, boiled mushrooms, boiled chicken, and fresh cream. Simmer for 5-6 minutes until cooked well.
Prepare Tadka: In a pan, heat oil. Add chopped garlic cloves and sauté until golden. Add dry Kashmiri red chillies, coriander leaves, and butter; sauté for a minute. Finish with lemon juice and set aside.
Finish Dish: Add prepared tadka to the creamy chicken mixture. Mix well. Transfer to serving dish, garnish with coriander sprig, and serve hot with roti or rice.