Warm the oil in a non-stick frying pan over medium heat, then cook the minced onion for 3 to 4 minutes. The onion should turn golden and give off a gentle sizzle without developing dark or burnt edges.

Stir in the garlic and ginger for 1 minute, then add the cubed chicken and cook for about 5 minutes, stirring often. The aromatics should smell fragrant, and the chicken should look opaque on the outside with no pink remaining in the center.

Add the pureed tomatoes, green chilli, yoghurt, turmeric, paprika, chilli powder, garam masala, black pepper, coriander powder, cardamon pods, and salt; cook for 2 minutes before pouring in the chicken broth. The tomatoes should begin to soften and the pan should return to a gentle simmer once the broth is added.

Reduce the heat to medium, cover the pan, and cook for about 15 minutes, stirring a couple of times. The sauce should become richer and the chicken should yield easily when pressed with a fork.

Remove the lid and stir in the red pepper, adding a touch more stock or water if the curry needs loosening, then cover and cook for 3 to 5 minutes. The pepper should be cooked through while still holding a crisp-tender bite.

Stir through the chopped coriander, remove the cardamon pods, and squeeze their seeds into the curry. The finished sauce should look glossy and aromatic, with a final fresh lift from the coriander.