Heat ½ teaspoon of oil in a pan over medium heat. Add the finely chopped onions, garlic, and ginger. Sauté until the onions turn translucent and develop a light golden colour. Add the grated coconut to the pan and continue sautéing until the coconut turns golden brown and aromatic. Transfer to a plate to cool completely.

In the same pan (no need to wash), add all the whole spices: Kashmiri red chillies, poppy seeds, cloves, cinnamon stick, black peppercorns, cumin seeds, coriander seeds, fennel seeds, turmeric powder, sesame seeds, and fenugreek seeds. Roast them on a low flame for 3-5 minutes. The spices are ready when they release a fragrant aroma and just begin to turn brown. Turn off the heat and let the spices cool.

Transfer the cooled roasted spices and the onion-coconut mixture to a grinder or blender. Grind into a smooth paste, adding a little water for better blending. The paste should be thick and aromatic.

Heat 2 tablespoons of oil in a deep pan over medium heat. Add the ground masala paste and cook for 5 minutes, stirring frequently to prevent sticking. Add the marinated chicken pieces and cook for 5 minutes with constant stirring, ensuring the chicken is coated with the masala. Add enough water for the gravy and bring to a boil. Reduce the heat and continue cooking until the chicken is tender and fully cooked, about 15 minutes. Add the tamarind water and simmer for another 5-7 minutes on a low flame.

Turn off the heat. Garnish with freshly chopped coriander leaves. Taste and adjust salt if needed. Let it rest for a few minutes before serving.