Heat the vegetable oil in a large pan over medium heat.

Add the cumin seeds, fennel seeds, dried red chillies, cloves, green cardamom pods, black peppercorns, mustard seeds, and fenugreek seeds. Cook for 1-2 minutes until aromatic.

Add the chopped onions to the pan and cook until they turn translucent, about 5 minutes.

Stir in the minced garlic and grated ginger, cook for another 2 minutes.

Add the turmeric powder, coriander powder, cinnamon powder, ground nutmeg, and ground mace. Stir well to combine with the onion mixture.

Add the chicken thighs to the pan and cook until they are browned on all sides, about 5-7 minutes.

Pour in enough water to cover the chicken, then add the tamarind paste and season with salt to taste.

Bring the mixture to a simmer, then cover and cook for 30-35 minutes, or until the chicken is cooked through and tender.

Once cooked, remove from heat and garnish with chopped fresh coriander leaves.

Serve the Chicken Xacuti hot with rice or bread.