Start by chopping your onions very finely. Peel and grate the fresh ginger. Crush the garlic cloves. Having these ready makes the cooking process smooth and stress-free. Your kitchen will already start smelling amazing.

Heat the vegetable oil in your large pan over medium heat. Add the chicken chunks. Cook them until they are lightly browned on all sides. You do not need to cook them through yet. Remove and set aside.

In the same pan, add the chopped onions. Cook them gently for about 8 to 10 minutes. You want them to be soft and translucent. Do not rush this step. Sweet onions make a better sauce.

Stir in the grated ginger and crushed garlic. Cook them with the onions for another minute. This releases their natural oils and fragrance. Be careful not to burn the garlic, or it might turn bitter.

Add the curry powder, turmeric, and cumin to the pan. Stir well to coat the onions. Toast the spices for about one minute. This "wakes up" the flavors and removes the raw taste of the powder.

Pour in the chopped tomatoes and the tomato purée. Stir in the chicken stock and the sugar. Bring the mixture to a gentle simmer. The sauce will look bright and vibrant at this stage.

Add the browned chicken back into the pan. Stir everything together so the chicken is submerged. Lower the heat and simmer for about 15 to 20 minutes. The sauce should thicken and become rich.

Taste your curry carefully. Add salt and pepper as needed. If the sauce is too thick, add a splash of water. Turn off the heat. Sprinkle a generous handful of fresh coriander over the top.