Heat 2 teaspoons vegetable oil in a frying pan or curry pan over a medium heat. 1 small onion, roughly chopped and stir-fry for 2 minutes.
Add 80 millilitres curry broth, 1 teaspoon garlic ginger paste, 1 teaspoon tomato puree, 1/4 teaspoon mild red chilli powder, 1 teaspoon dried fenugreek leaves (methi), pinch sea salt and 1 small handful fresh coriander leaves, finely chopped. Bring to the boil. Add 1 portion cooked chicken for curry dishes and another 80 millilitres curry broth. Mix well and simmer for 2 minutes.
Add the remaining 80 millilitres curry broth and simmer for another 2 minutes until the dopiaza curry sauce is medium thick. Transfer the chicken dopiaza curry to a serving bowl and finish with a little more fresh coriander and 1/2 small onion, very thinly sliced. Serve with your favourite Indian rice and breads.