Begin by creating a smooth paste by blending garlic and fresh ginger with a splash of water. In a bowl, combine this paste with yogurt and mild chili powder, then add the boneless chicken thighs. Ensure each piece is well-coated and allow the chicken to marinate for at least 1 hour, preferably overnight, in the refrigerator to enhance flavor.

In a blender, combine finely chopped tomatoes with tomato purée, blending until smooth. Set this mixture aside; it will serve as the vibrant base for your Chicken Bhuna, adding both acidity and richness to the curry.

Heat vegetable oil in a large frying pan over medium heat. Once hot, toss in the dried red chillies and let them infuse the oil for a minute. Next, add the finely chopped onions and sauté them for about 25 minutes or until they turn golden brown.

Once your onions are beautifully caramelized, stir in the tomato paste and cook for an additional 5 minutes, allowing the flavors to meld. Now, introduce the marinated chicken to the pan. Cook for about 6 minutes, consistently stirring to ensure that the chicken is well-coated.

Season the dish with salt to taste, then reduce the heat and cover the pan. Let the Chicken Bhuna simmer for approximately 8 minutes, stirring halfway through.

Finally, add the fennel seeds, freshly ground black pepper, and garam masala into the curry. Stir gently and let it cook for a couple of minutes on low heat to meld the spices together. Once done, garnish with freshly chopped coriander.