Heat the oil in a large frying pan over medium-high heat. When visibly hot, add the chopped onions and fry for three to five minutes or until soft and translucent.
Stir in the garlic and ginger paste and fry for 30 seconds, then add the blended habanero chillies.
Stir in the Mr Naga paste.
Add the mixed powder and Kashmiri chilli powder followed by the tomato puree and stir to combine, then add about 125ml (½ cup) of the base sauce.
Allow this to come to a simmer. This is a good time to add the pre-cooked lamb. Stir to coat in the sauce.
Add more base sauce whenever the curry is looking dry and simmer again, only stirring if the sauce is sticking to the pan. As you cook, the sauce will caramelise to the side of the pan. Stir this in as it adds flavour.
Season with salt to taste. Sprinkle the kasoori methi over the top by rubbing it between your fingers.
To serve, garnish with the garam masala and coriander.
