Heat oil in a pressure cooker. Crackle the cumin seeds.
Add the ginger garlic paste and saute till raw smell is gone.
Add the onions and green chillies and cook till witled.
Add the mutton and fry till it becomes whitish.
Add in the powders and cook for a couple of minutes
Add in beetroot, tomato and salt to taste, mix well.
Close the lid of the pressure cooker and cook on high flame for 3 whistles and on simmer for 15 minutes. Switch off and allow pressure to go by itself.
Open the lids, check seasoning. Sprinkle in garam masala powder and kasuri methi, give it a simmer.
Serve hot with naans or rice with coriander leaves as garnish.
Notes
I didn't add any water to the gravy. The fluid you see is the mutton stock. If cooking on stove top, make sure to add sufficient water for fluid, so that it doesn't get stuck to the bottom of the pan.