Start by blending garlic and fresh root ginger with a splash of water until smooth to create a fragrant paste. In a bowl, combine this paste with Greek-style yoghurt and the seasoning mix, coating the boneless chicken thighs thoroughly. Cover and let them marinate in the refrigerator for at least 1 hour, or if time allows, overnight for deeper flavor absorption.

While the chicken marinates, prepare the tomato base. Blend the finely chopped tomatoes with tomato purée until they reach a smooth consistency. Set this mixture aside.

In a large frying pan, heat vegetable oil over medium heat. Once hot, add the dried red chillies and sauté for about 1 minute until fragrant. Then, toss in the finely chopped onions, cooking them for approximately 25 minutes until they are golden brown and caramelized, stirring frequently.

Next, stir in the tomato paste with the cooked onions and allow it to simmer for about 5 minutes. Gently add the marinated chicken thighs to the pan, stirring well to coat them with the mixture. Cook for about 6 minutes.

Now, season the mixture with a pinch of salt to bring out all the flavors. Reduce the heat to low, covering the pan tightly. Allow the Chicken Bhuna to simmer for about 8 minutes, stirring halfway through.

Finally, uncover and add the fennel seeds, black pepper, and garam masala to the curry. Stir everything well, letting the thick sauce envelop each piece of chicken. Heat for an additional couple of minutes, then remove from the heat. Garnish with freshly chopped coriander before serving.