Wash the lamb and pat dry.
In a small bowl, mix together the ginger-garlic paste, yogurt, turmeric, Kashmiri chili powder, and salt and use this mixture to marinate the lamb. Keep the marinated lamb in the fridge for 1 hour at least.
Turn on the Instant Pot in Sauté mode.
Add the ghee or vegetable oil along with the onions, and sauté until the onions are translucent. This should take 5-6 minutes.
Add the sliced tomatoes and cook for 5 minutes.
Add the cumin powder and fennel powder and stir for a minute.
Add the marinated lamb and mix well to combine all the ingredients.
Add the tomato puree followed by 1/3 cup water and make sure to deglaze the pan, picking up any bits of residue that may have stuck to the bottom of the pot. Not deglazing the pot can lead to a burn error.
Close lid of the IP and turn the vent to ‘Sealing’ position. Pressure cook at 15 minutes and let the steam release naturally.
Once the valve comes down, open the lid, add the garam masala and stir.
Switch to Sauté mode and simmer for 5 minutes until the gravy has thickened slightly.
Garnish with chopped coriander leaves and slivers of ginger.
Serve along with rice.