Start by creating a paste of garlic and fresh ginger blended with a little water. In a mixing bowl, combine this paste with yogurt, mild chili powder, turmeric, cumin, ground coriander, and salt. Add boneless chicken thighs to the marinade, ensuring each piece is well coated. Cover and let it marinate in the fridge for at least 1 hour, or ideally overnight, to develop rich flavors.

While the chicken marinates, blend the chopped tomatoes with tomato purée in a blender until smooth. This mixture will form the base of the Chicken Bhuna. Set it aside, as it will be added to the pan shortly, bringing fresh acidity and depth to the curry.

In a large frying pan, heat vegetable oil over medium heat. Once hot, add dried red chilies, allowing them to sizzle for a minute. Then, add the finely chopped onions and sauté them for about 25 minutes, stirring frequently until they turn golden brown.

Stir in the reserved tomato base and cook for another 5 minutes, allowing it to thicken slightly. Next, add the marinated chicken to the pan, spreading it evenly across the mixture. Let it cook uncovered for about 6 minutes until the chicken is lightly seared and the outside becomes opaque.

Season the mixture with additional salt to taste. Lower the heat to medium-low, cover the pan with a lid, and let it simmer for about 8 minutes, stirring halfway through.

Uncover the pan and mix in fennel seeds, freshly ground black pepper, and garam masala. Stir well to combine all the spices, then cook for an extra couple of minutes to fully incorporate the flavors. Garnish your Chicken Bhuna with fresh coriander before serving it hot.